Undergraduate instrumental analysis 7e by frame, eileen m skelly frame, george m robinson, james w

SEVENTH EDITION

Undergraduate
Instrumental
Analysis



SEVENTH EDITION

Undergraduate
Instrumental
Analysis
James W. Robinson

Department of Chemistry, Louisiana State University
Baton Rouge, Louisiana, USA

Eileen M. Skelly Frame

Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute
Troy, New York, USA

George M. Frame II

Wadsworth Laboratory, New York State Department of Health
Albany, New York, USA

Boca Raton London New York

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Contents
Preface.............................................................................................................................................xxi
Acknowledgments...........................................................................................................................xxv
Authors...........................................................................................................................................xxix
Chapter 1
Concepts of Instrumental Analytical Chemistry................................................................................1
1.1
1.2

Introduction: What Is Analytical Chemistry?.......................................................................... 1
Analytical Approach................................................................................................................3
1.2.1 Defining the Problem.................................................................................................. 3
1.2.1.1 Qualitative Analysis.................................................................................... 4
1.2.1.2 Quantitative Analysis..................................................................................7
1.2.2 Designing the Analytical Method............................................................................. 12
1.2.3Sampling................................................................................................................... 14
1.2.3.1 Gas Samples.............................................................................................. 16
1.2.3.2 Liquid Samples.......................................................................................... 17
1.2.3.3 Solid Samples............................................................................................ 18
1.2.4 Storage of Samples.................................................................................................... 18
1.3 Basic Statistics and Data Handling........................................................................................ 19
1.3.1 Significant Figures.................................................................................................... 19
1.3.2 Accuracy and Precision............................................................................................ 21
1.3.3 Types of Errors.......................................................................................................... 23

1.3.3.1 Determinate Error..................................................................................... 23
1.3.3.2 Indeterminate Error................................................................................... 27
1.3.4 Definitions for Statistics............................................................................................28
1.3.5 Quantifying Random Error....................................................................................... 29
1.3.5.1 Confidence Limits..................................................................................... 33
1.3.5.2Variance....................................................................................................34
1.3.6 Rejection of Results.................................................................................................. 35
1.4 Sample Preparation................................................................................................................ 36
1.4.1 Acid Dissolution and Digestion................................................................................ 37
1.4.2Fusions...................................................................................................................... 39
1.4.3 Dry Ashing and Combustion....................................................................................40
1.4.4Extraction..................................................................................................................40
1.4.4.1 Solvent Extraction..................................................................................... 41
1.4.4.2 Solid-Phase Extraction..............................................................................44
1.4.4.3QuEChERS............................................................................................... 45
1.4.4.4 Solid-Phase Microextraction.....................................................................46
1.5 Performing the Measurement................................................................................................. 49
1.5.1 Signals and Noise...................................................................................................... 49
1.5.2 Plotting Calibration Curves...................................................................................... 52
1.6 Assessing the Data................................................................................................................. 54
1.6.1 Limit of Detection..................................................................................................... 55
1.6.2 Limit of Quantitation................................................................................................ 56
Problems........................................................................................................................................... 56
Bibliography...................................................................................................................................... 59

iii


iv

Contents

Chapter 2
Introduction to Spectroscopy............................................................................................................ 61
2.1

Interaction between Electromagnetic Radiation and Matter................................................. 61
2.1.1 What Is Electromagnetic Radiation?........................................................................ 61
2.1.2 How Does Electromagnetic Radiation Interact with Matter?...................................64
2.2 Atoms and Atomic Spectroscopy........................................................................................... 68
2.3 Molecules and Molecular Spectroscopy................................................................................ 70
2.3.1 Rotational Transitions in Molecules......................................................................... 70
2.3.2 Vibrational Transitions in Molecules........................................................................ 70
2.3.3 Electronic Transitions in Molecules......................................................................... 71
2.4 Absorption Laws.................................................................................................................... 72
2.4.1 Deviations from Beer’s Law..................................................................................... 75
2.5 Methods of Calibration.......................................................................................................... 76
2.5.1 Calibration with Standards....................................................................................... 76
2.5.2 Method of Standard Additions.................................................................................. 79
2.5.3 Internal Standard Calibration................................................................................... 82
2.5.4 Errors Associated with Beer’s Law Relationships.................................................... 85
2.6 Optical Systems Used in Spectroscopy.................................................................................. 88
2.6.1 Radiation Sources..................................................................................................... 89
2.6.2 Wavelength Selection Devices..................................................................................90
2.6.2.1Filters.........................................................................................................90
2.6.2.2Monochromator.........................................................................................90
2.6.2.3 Resolution Required to Separate Two Lines of Different Wavelengths...... 94
2.6.3 Optical Slits............................................................................................................... 98
2.6.4Detectors................................................................................................................. 101
2.6.5 Single-Beam and Double-Beam Optics.................................................................. 101

2.6.6 Dispersive Optical Layouts..................................................................................... 104
2.6.7 Fourier Transform Spectrometers........................................................................... 105
2.6.7.1 Advantages of FT Systems...................................................................... 107
2.7 Spectroscopic Technique and Instrument Nomenclature.................................................... 107
Suggested Experiments................................................................................................................... 108
Problems......................................................................................................................................... 109
Bibliography.................................................................................................................................... 111

Chapter 3
Magnetic Resonance Spectroscopy................................................................................................ 113
3.1

3.2

Introduction to Nuclear Magnetic Resonance Spectroscopy............................................... 113
3.1.1 Properties of Nuclei................................................................................................ 114
3.1.2 Quantization of 1H Nuclei in a Magnetic Field....................................................... 116
3.1.2.1 Saturation and Magnetic Field Strength.................................................. 119
3.1.3 Width of Absorption Lines..................................................................................... 121
3.1.3.1 Homogeneous Field................................................................................. 121
3.1.3.2 Relaxation Time...................................................................................... 122
3.1.3.3 Magic Angle Spinning............................................................................ 123
3.1.3.4 Other Sources of Line Broadening.......................................................... 124
FT-NMR Experiment........................................................................................................... 124


Contents

v

3.3 Chemical Shifts.................................................................................................................... 127
3.4 Spin–Spin Coupling............................................................................................................. 134
3.5Instrumentation.................................................................................................................... 146
3.5.1 Sample Holder......................................................................................................... 146
3.5.2 Sample Probe.......................................................................................................... 148
3.5.3Magnet.................................................................................................................... 150
3.5.4 RF Generation and Detection................................................................................. 151
3.5.5 Signal Integrator and Computer.............................................................................. 152
3.6 Analytical Applications of NMR......................................................................................... 152
3.6.1 Samples and Sample Preparation for NMR............................................................ 153
3.6.2 Qualitative Analyses: Molecular Structure Determination.................................... 153
3.6.2.1 Relationship between the Area of a Peak and Molecular
Structure. . .....................................................................................153
3.6.2.2 Chemical Exchange................................................................................. 154
3.6.2.3 Double-Resonance Experiments............................................................. 155
3.6.3 Interpretation of Proton Spectra............................................................................. 160
3.6.3.1 Aliphatic Alkanes, Alkenes, Alkynes, and Alkyl Halides..................... 161
3.6.3.2 Aromatic Compounds............................................................................. 167
3.6.3.3 Oxygen-Containing Organic Compounds............................................... 170
3.6.3.4 Nitrogen-Containing Organic Compounds............................................. 172
3.6.4 13C NMR................................................................................................................. 175
3.6.4.1 Heteronuclear Decoupling....................................................................... 178
3.6.4.2 Nuclear Overhauser Effect...................................................................... 179
3.6.4.3 13C NMR Spectra of Solids..................................................................... 180
3.6.4.4 Interpretation of 13C Spectra................................................................... 181
3.6.5 2D NMR................................................................................................................. 182
3.6.6 Qualitative Analyses: Other Applications.............................................................. 189
3.6.7 Quantitative Analyses............................................................................................. 191
3.7 Hyphenated NMR Techniques............................................................................................. 195
3.8 NMR Imaging and MRI...................................................................................................... 195

3.9 Time Domain NMR............................................................................................................. 201
3.9.1 Solid Fat Content Determination by TD-NMR...................................................... 203
3.9.2 Field Homogeneity and Spin Echo.........................................................................204
3.9.3 Relaxation Time Distribution.................................................................................207
3.9.4 TD-NMR Applications...........................................................................................208
3.10 Low-Field, Portable, and Miniature NMR Instruments......................................................209
3.11 Limitations of NMR............................................................................................................. 210
3.12 Electron Spin Resonance Spectroscopy............................................................................... 210
3.12.1Instrumentation....................................................................................................... 214
3.12.1.1 Samples and Sample Holders.................................................................. 217
3.12.2 Miniature ESR Spectroscopy................................................................................. 217
3.12.3 ESR Spectra and Hyperfine Interactions................................................................ 217
3.12.4Applications............................................................................................................ 221
3.12.4.1 Spin Labels and Spin Traps..................................................................... 223
3.12.5CW-ENDOR...........................................................................................................224
Suggested Experiments................................................................................................................... 226
Problems......................................................................................................................................... 227
Bibliography....................................................................................................................................240
Spectral Databases.......................................................................................................................... 241


vi

Contents

Chapter 4
Infrared, Near-Infrared, and Raman Spectroscopy........................................................................ 243
4.1

4.2

4.3

4.4
4.5
4.6

Absorption of IR Radiation by Molecules...........................................................................244
4.1.1 Dipole Moments in Molecules................................................................................ 245
4.1.2 Types of Vibrations in Molecules...........................................................................246
4.1.3 Vibrational Motion..................................................................................................248
IR Instrumentation............................................................................................................... 250
4.2.1 Radiation Sources................................................................................................... 254
4.2.1.1 Mid-IR Sources....................................................................................... 255
4.2.1.2 NIR Sources............................................................................................ 256
4.2.1.3 Far-IR Sources......................................................................................... 258
4.2.1.4 IR Laser Sources..................................................................................... 258
4.2.2 Monochromators and Interferometers.................................................................... 258
4.2.2.1 FT Spectrometers.................................................................................... 259
4.2.2.2 Interferometer Components..................................................................... 263
4.2.3Detectors.................................................................................................................264
4.2.3.1Bolometer................................................................................................264
4.2.3.2Thermocouples........................................................................................ 265
4.2.3.3Thermistors.............................................................................................266
4.2.3.4 Golay Detector........................................................................................266
4.2.3.5 Pyroelectric Detectors.............................................................................266
4.2.3.6 Photon Detectors..................................................................................... 267
4.2.4 Detector Response Time......................................................................................... 268
Sampling Techniques........................................................................................................... 268
4.3.1 Techniques for Transmission (Absorption) Measurements..................................... 269

4.3.1.1 Solid Samples.......................................................................................... 269
4.3.1.2 Liquid Samples........................................................................................ 271
4.3.1.3 Gas Samples............................................................................................ 273
4.3.2 Background Correction in Transmission Measurements........................................ 274
4.3.2.1 Solvent Absorption.................................................................................. 274
4.3.2.2 Air Absorption........................................................................................ 275
4.3.3 Techniques for Reflectance and Emission Measurements...................................... 275
4.3.3.1 Attenuated Total Reflectance.................................................................. 275
4.3.3.2 Specular Reflectance............................................................................... 277
4.3.3.3 Diffuse Reflectance................................................................................. 278
4.3.3.4 IR Emission.............................................................................................280
FTIR Microscopy................................................................................................................. 281
Nondispersive IR Systems................................................................................................... 285
Analytical Applications of IR Spectroscopy....................................................................... 287
4.6.1 Qualitative Analyses and Structural Determination by Mid-IR
Absorption Spectroscopy........................................................................................ 289
4.6.1.1Hydrocarbons.......................................................................................... 291
4.6.1.2 Organic Compounds with C–O Bonds................................................... 297
4.6.1.3 Nitrogen-Containing Organic Compounds.............................................302
4.6.1.4 Functional Groups Containing Heteroatoms.......................................... 305
4.6.2 Quantitative Analyses by IR Spectrometry............................................................309


Contents

vii

4.7

NIR Spectroscopy................................................................................................................ 313

4.7.1Instrumentation....................................................................................................... 313
4.7.2 NIR Vibrational Bands, Spectral Interpretation, and Calibration.......................... 314
4.7.2.1 NIR Calibration: Chemometrics............................................................. 316
4.7.3 Sampling Techniques for NIR Spectroscopy.......................................................... 316
4.7.3.1 Liquids and Solutions.............................................................................. 317
4.7.3.2Solids....................................................................................................... 318
4.7.3.3Gases....................................................................................................... 320
4.7.4 Applications of NIR Spectroscopy......................................................................... 320
4.8 Raman Spectroscopy............................................................................................................ 321
4.8.1 Principles of Raman Scattering.............................................................................. 322
4.8.2 Raman Instrumentation.......................................................................................... 325
4.8.2.1 Light Sources........................................................................................... 325
4.8.2.2 Dispersive Spectrometer Systems........................................................... 325
4.8.2.3 FT-Raman Spectrometers....................................................................... 326
4.8.2.4 Fiber-Optic-Based Modular and Handheld Systems............................... 327
4.8.2.5 Samples and Sample Holders for Raman Spectroscopy......................... 330
4.8.3 Applications of Raman Spectroscopy..................................................................... 330
4.8.4 Resonance Raman Effect........................................................................................ 336
4.8.5 Surface-Enhanced Raman Spectroscopy................................................................ 336
4.8.6 Raman Microscopy................................................................................................. 338
4.9 Chemical Imaging Using NIR, IR, and Raman Spectroscopy............................................340
Suggested Experiments................................................................................................................... 348
Problems......................................................................................................................................... 348
Bibliography.................................................................................................................................... 354
Spectral Databases.......................................................................................................................... 356
Chapter 5
Visible and Ultraviolet Molecular Spectroscopy............................................................................ 357
5.1Introduction.......................................................................................................................... 357
5.1.1 Electronic Excitation in Molecules......................................................................... 361
5.1.2 Absorption by Molecules........................................................................................364

5.1.3 Molar Absorptivity................................................................................................. 365
5.1.4 Shape of UV Absorption Curves............................................................................ 367
5.1.5 Solvents for UV/VIS Spectroscopy........................................................................ 370
5.2Instrumentation.................................................................................................................... 370
5.2.1 Optical System........................................................................................................ 370
5.2.2 Radiation Sources................................................................................................... 371
5.2.3Monochromators..................................................................................................... 374
5.2.4Detectors................................................................................................................. 374
5.2.4.1 Barrier Layer Cell................................................................................... 374
5.2.4.2 Photomultiplier Tube............................................................................... 376
5.2.4.3 Semiconductor Detectors: Diodes and Diode Array Systems................. 377
5.2.4.4Diodes...................................................................................................... 379
5.2.4.5 Diode Arrays........................................................................................... 380
5.2.5 Sample Holders....................................................................................................... 382
5.2.5.1 Liquid and Gas Cells............................................................................... 382


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5.2.5.2 Matched Cells.......................................................................................... 384
5.2.5.3 Flow-Through Samplers.......................................................................... 385
5.2.5.4 Solid Sample Holders.............................................................................. 385
5.2.5.5 Fiber-Optic Probes.................................................................................. 386
5.2.6 Microvolume, Nanovolume, and Handheld UV/VIS Spectrometers...................... 386
5.2.6.1 Microvolume Systems............................................................................. 387
5.2.6.2 Variable Path Length Slope Spectroscopy™ System.............................. 391
5.2.6.3 Handheld Visible Spectroscopy System.................................................. 394
5.3 UV Absorption Spectra of Molecules.................................................................................. 395

5.3.1 Solvent Effects on UV Spectra............................................................................... 396
5.3.1.1 Bathochromic or Red Shift..................................................................... 396
5.3.1.2 Hypsochromic or Blue Shift.................................................................... 396
5.4 UV Spectra and the Structure of Organic Molecules.......................................................... 398
5.4.1 Conjugated Diene Systems..................................................................................... 398
5.4.2 Conjugated Ketone Systems................................................................................... 401
5.4.3 Substitution of Benzene Rings................................................................................404
5.5 Analytical Applications.......................................................................................................406
5.5.1 Qualitative Structural Analysis...............................................................................406
5.5.2 Quantitative Analysis..............................................................................................407
5.5.3 Multicomponent Determinations............................................................................ 412
5.5.4 Other Applications.................................................................................................. 413
5.5.4.1 Reaction Kinetics.................................................................................... 413
5.5.4.2 Spectrophotometric Titrations................................................................. 414
5.5.4.3Spectroelectrochemistry.......................................................................... 415
5.5.4.4 Analysis of Solids.................................................................................... 415
5.5.5 Measurement of Color............................................................................................ 416
5.6 Accuracy and Precision in UV/VIS Absorption Spectrometry........................................... 418
5.7 Nephelometry and Turbidimetry.......................................................................................... 419
5.8 Molecular Emission Spectrometry....................................................................................... 420
5.8.1 Fluorescence and Phosphorescence........................................................................ 420
5.8.2 Relationship between Fluorescence Intensity and Concentration.......................... 423
5.9 Instrumentation for Luminescence Measurements.............................................................. 425
5.9.1 Wavelength Selection Devices................................................................................ 425
5.9.2 Radiation Sources................................................................................................... 426
5.9.3Detectors................................................................................................................. 428
5.9.4 Sample Cells........................................................................................................... 428
5.9.5 Spectrometer Systems............................................................................................. 428
5.10 Analytical Applications of Luminescence........................................................................... 429
5.10.1 Advantages of Fluorescence and Phosphorescence................................................ 431

5.10.2 Disadvantages of Fluorescence and Phosphorescence........................................... 431
Suggested Experiments................................................................................................................... 432
Problems......................................................................................................................................... 434
Bibliography.................................................................................................................................... 439
Chapter 6
Atomic Absorption Spectrometry................................................................................................... 441
6.1

Absorption of Radiant Energy by Atoms............................................................................. 441
6.1.1 Spectral Linewidth..................................................................................................444


Contents

ix

6.1.2 Degree of Radiant Energy Absorption...................................................................444
6.2Instrumentation.................................................................................................................... 445
6.2.1 Radiation Sources................................................................................................... 445
6.2.1.1 Hollow Cathode Lamp............................................................................ 445
6.2.1.2 Electrodeless Discharge Lamp................................................................448
6.2.2Atomizers................................................................................................................448
6.2.2.1 Flame Atomizers.....................................................................................449
6.2.2.2 Electrothermal Atomizers....................................................................... 451
6.2.2.3 Other Atomizers...................................................................................... 453
6.2.3 Spectrometer Optics................................................................................................ 454
6.2.3.1Monochromator....................................................................................... 454
6.2.3.2 Optics and Spectrometer Configuration.................................................. 455
6.2.4Detectors................................................................................................................. 456
6.2.5Modulation.............................................................................................................. 456

6.2.6 Commercial AAS Systems..................................................................................... 457
6.2.6.1 High-Resolution Continuum Source AAS.............................................. 458
6.3 Atomization Process............................................................................................................ 459
6.3.1 Flame Atomization................................................................................................. 459
6.3.2 Graphite Furnace Atomization...............................................................................464
6.4 Interferences in AAS...........................................................................................................466
6.4.1 Nonspectral Interferences.......................................................................................466
6.4.1.1 Chemical Interference.............................................................................466
6.4.1.2 Matrix Interference................................................................................. 467
6.4.1.3 Ionization Interference............................................................................468
6.4.1.4 Nonspectral Interferences in GFAAS.....................................................469
6.4.1.5 Chemical Modification............................................................................ 470
6.4.2 Spectral Interferences............................................................................................. 472
6.4.2.1 Atomic Spectral Interference.................................................................. 472
6.4.2.2 Background Absorption and Its Correction............................................ 473
6.4.2.3 Two-Line Background Correction.......................................................... 473
6.4.2.4 Continuum Source Background Correction............................................ 474
6.4.2.5 Zeeman Background Correction............................................................. 475
6.4.2.6 Smith–Hieftje Background Corrector..................................................... 477
6.4.2.7 Spectral Interferences in GFAAS........................................................... 479
6.5 Analytical Applications of AAS.......................................................................................... 479
6.5.1 Qualitative Analysis................................................................................................480
6.5.2 Quantitative Analysis..............................................................................................480
6.5.2.1 Quantitative Analytical Range................................................................480
6.5.2.2Calibration............................................................................................... 481
6.5.3 Analysis of Samples................................................................................................ 483
6.5.3.1 Liquid Samples........................................................................................ 483
6.5.3.2 Solid Samples.......................................................................................... 483
6.5.3.3 Gas Samples............................................................................................ 485
6.5.3.4 Cold Vapor Mercury Technique.............................................................. 487

6.5.3.5 Hydride Generation Technique............................................................... 488
6.5.3.6 Flow Injection Analysis........................................................................... 488
6.5.3.7 Flame Microsampling............................................................................. 489
Suggested Experiments................................................................................................................... 489
Problems......................................................................................................................................... 491


x

Contents

6.AAppendix.............................................................................................................................. 493
6.BAppendix.............................................................................................................................. 501
Bibliography.................................................................................................................................... 505

Chapter 7
Atomic Emission Spectroscopy...................................................................................................... 507
7.1

7.2

7.3

7.4

Flame Atomic Emission Spectroscopy................................................................................ 508
7.1.1 Instrumentation for Flame OES..............................................................................509
7.1.1.1 Burner Assembly.....................................................................................509
7.1.1.2 Wavelength Selection Devices................................................................ 510
7.1.1.3Detectors................................................................................................. 510

7.1.1.4 Flame Excitation Source......................................................................... 510
7.1.2Interferences............................................................................................................ 513
7.1.2.1 Chemical Interference............................................................................. 513
7.1.2.2 Excitation and Ionization Interferences.................................................. 513
7.1.2.3 Spectral Interferences.............................................................................. 514
7.1.3 Analytical Applications of Flame OES.................................................................. 515
7.1.3.1 Qualitative Analysis................................................................................ 515
7.1.3.2 Quantitative Analysis.............................................................................. 516
Atomic OES......................................................................................................................... 519
7.2.1 Instrumentation for Emission Spectroscopy........................................................... 520
7.2.1.1 Electrical Excitation Sources.................................................................. 520
7.2.1.2 Sample Holders....................................................................................... 526
7.2.1.3Spectrometers.......................................................................................... 527
7.2.1.4Detectors................................................................................................. 529
7.2.2 Interferences in Arc and Spark Emission Spectroscopy......................................... 534
7.2.2.1 Matrix Effects and Sample Preparation.................................................. 534
7.2.2.2 Spectral Interference............................................................................... 535
7.2.2.3 Internal Standard Calibration.................................................................. 535
7.2.3 Applications of Arc and Spark Emission Spectroscopy......................................... 536
7.2.3.1 Qualitative Analysis................................................................................ 536
7.2.3.2 Raies Ultimes.......................................................................................... 537
7.2.3.3 Quantitative Analysis.............................................................................. 538
Plasma Emission Spectroscopy............................................................................................540
7.3.1 Instrumentation for Plasma Emission Spectrometry..............................................540
7.3.1.1 Excitation Sources...................................................................................540
7.3.1.2 Spectrometer Systems for ICP, DCP, and MP......................................... 547
7.3.1.3 Sample Introduction Systems.................................................................. 549
7.3.2 Interferences and Calibration in Plasma Emission Spectrometry.......................... 555
7.3.2.1 Chemical and Ionization Interference..................................................... 556
7.3.2.2 Spectral Interference and Correction...................................................... 557

7.3.3 Applications of ICP, DCP, and MP Atomic Emission Spectroscopy..................... 561
7.3.4 Chemical Speciation with Hyphenated Instruments.............................................. 563
GD Emission Spectrometry.................................................................................................564
7.4.1 DC and RF GD Sources..........................................................................................564
7.4.2 Applications of GD Atomic Emission Spectrometry............................................. 565
7.4.2.1 Bulk Analysis.......................................................................................... 565
7.4.2.2 Depth Profile Analysis............................................................................ 566


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xi

7.5AFS...................................................................................................................................... 567
7.5.1 Instrumentation for AFS......................................................................................... 569
7.5.2 Interferences in AFS............................................................................................... 570
7.5.2.1 Chemical Interference............................................................................. 570
7.5.2.2 Spectral Interference............................................................................... 570
7.5.3 Applications of AFS............................................................................................... 571
7.5.3.1 Graphite Furnace Laser-Excited AFS..................................................... 571
7.5.3.2 Mercury Determination and Speciation by AFS.................................... 572
7.5.3.3 Hydride Generation and Speciation by AFS........................................... 572
7.6 Commercial Atomic Emission Systems............................................................................... 573
7.6.1 Arc and Spark Systems........................................................................................... 573
7.6.2 ICP, DCP, and MP Systems.................................................................................... 573
7.6.3 GD Systems............................................................................................................. 574
7.6.4 AFS Systems........................................................................................................... 574
7.7 Laser-Induced Breakdown Spectroscopy............................................................................. 574
7.7.1 Principle of Operation............................................................................................. 575
7.7.2Instrumentation....................................................................................................... 575

7.7.3 Applications of LIBS.............................................................................................. 577
7.7.3.1 Qualitative Analysis and Semiquantitative Analysis.............................. 578
7.7.3.2 Quantitative Analysis.............................................................................. 579
7.7.3.3 Remote Analysis...................................................................................... 580
7.7.4 Commercial LIBS Systems..................................................................................... 582
7.8 Atomic Emission Literature and Resources......................................................................... 582
7.9 Comparison of Atomic Spectroscopic and ICP-MS Techniques......................................... 583
Suggested Experiments................................................................................................................... 584
Problems......................................................................................................................................... 585
7.AAppendix.............................................................................................................................. 588
7.B Appendix: Comparison of Atomic Spectroscopic Analytical Techniques.......................... 590
Bibliography.................................................................................................................................... 593
Chapter 8
X-Ray Spectroscopy........................................................................................................................ 595
Contributing authors: Alexander Seyfarth and Eileen Skelly Frame
8.1

8.2

Origin of X-Ray Spectra...................................................................................................... 595
8.1.1 Energy Levels in Atoms.......................................................................................... 595
8.1.2 Moseley’s Law........................................................................................................602
8.1.3 X-Ray Methods.......................................................................................................603
8.1.3.1 X-Ray Absorption Process......................................................................603
8.1.3.2 X-Ray Fluorescence Process...................................................................605
8.1.3.3 X-Ray Diffraction Process......................................................................605
X-Ray Fluorescence.............................................................................................................608
8.2.1 X-Ray Source..........................................................................................................609
8.2.1.1 X-Ray Tube.............................................................................................. 610
8.2.1.2 Secondary XRF Sources......................................................................... 614

8.2.1.3 Radioisotope Sources.............................................................................. 615
8.2.2 Instrumentation for Energy Dispersive X-Ray Spectrometry................................. 615
8.2.2.1 Excitation Source.................................................................................... 618
8.2.2.2 Primary Beam Modifiers........................................................................ 618


xii

Contents

8.2.2.3 Sample Holders....................................................................................... 621
8.2.2.4 EDXRF Detectors................................................................................... 625
8.2.2.5 Multichannel Pulse Height Analyzer...................................................... 628
8.2.2.6 Detector Artifact Escape Peaks and Sum Peaks..................................... 629
8.2.3 Instrumentation for Wavelength-Dispersive X-Ray Spectrometry......................... 630
8.2.3.1Collimators.............................................................................................. 630
8.2.3.2 Analyzing Crystals.................................................................................. 633
8.2.3.3Detectors................................................................................................. 637
8.2.3.4 Electronic Pulse Processing Units.......................................................... 643
8.2.3.5 Sample Changers.....................................................................................644
8.2.4 Simultaneous WDXRF Spectrometers...................................................................644
8.2.5 Micro-XRF Instrumentation................................................................................... 645
8.2.5.1 Micro-X-Ray Beam Optics......................................................................646
8.2.5.2 Micro-XRF System Components............................................................ 647
8.2.6 Total Reflection XRF..............................................................................................648
8.2.7 Comparison between EDXRF and WDXRF..........................................................648
8.2.8 XRF Applications................................................................................................... 649
8.2.8.1 Analyzed Layer....................................................................................... 650
8.2.8.2 Sample Preparation Considerations for XRF.......................................... 652
8.2.8.3 Qualitative Analysis by XRF.................................................................. 655

8.2.8.4 Quantitative Analysis by XRF................................................................ 659
8.2.8.5 Applications of Quantitative XRF.......................................................... 662
8.3 X-Ray Absorption................................................................................................................664
8.3.1EXAFS.................................................................................................................... 669
8.4 X-Ray Diffraction................................................................................................................ 670
8.4.1 Single-Crystal X-Ray Diffractometry.................................................................... 673
8.4.2 Crystal Growing...................................................................................................... 676
8.4.3 Crystal Structure Determination............................................................................ 676
8.4.4 Powder X-Ray Diffractometry................................................................................ 676
8.4.5 Hybrid XRD/XRF Systems.................................................................................... 679
8.4.5.1 Compact and Portable Hybrid Systems...................................................680
8.4.6 Applications of XRD.............................................................................................. 681
8.4.6.1 Analytical Limitations of XRD..............................................................684
8.5 X-Ray Emission...................................................................................................................684
8.5.1 Electron Probe Microanalysis.................................................................................684
8.5.2 Particle-Induced X-Ray Emission........................................................................... 686
8.6 Commercial X-Ray Instrument Manufacturers................................................................... 686
Suggested Experiments/Tutorials................................................................................................... 688
Problems......................................................................................................................................... 689
8.A Appendix: Characteristic X-Ray Wavelengths (Å) and Energies (keV).............................. 695
8.B Appendix: Absorption Edge Wavelengths and Energies..................................................... 699
Bibliography.................................................................................................................................... 704
Chapter 9
Mass Spectrometry I: Principles and Instrumentation................................................................... 705
9.1

Principles of MS................................................................................................................... 705
9.1.1 Resolving Power and Resolution of a Mass Spectrometer...................................... 711
9.2Instrumentation.................................................................................................................... 713
9.2.1 Sample Input Systems............................................................................................. 713

Contents

xiii

9.2.1.1 Gas Expansion......................................................................................... 713
9.2.1.2 Direct Insertion and Direct Exposure Probes......................................... 714
9.2.1.3 Chromatography and Electrophoresis Systems....................................... 715
9.2.2 Ionization Sources................................................................................................... 715
9.2.2.1 Electron Ionization.................................................................................. 715
9.2.2.2 Chemical Ionization................................................................................ 716
9.2.2.3 Atmospheric Pressure Ionization Sources............................................... 718
9.2.2.4 Desorption Ionization.............................................................................. 722
9.2.2.5 Ionization Sources for Inorganic MS...................................................... 727
9.2.3 Mass Analyzers....................................................................................................... 728
9.2.3.1 Magnetic and Electric Sector Instruments.............................................. 730
9.2.3.2 Time-of-Flight Analyzer......................................................................... 734
9.2.3.3Quadrupole Mass Analyzer..................................................................... 741
9.2.3.4MS/MS and MSn Instruments................................................................. 743
9.2.3.5Quadrupole Ion Trap............................................................................... 746
9.2.3.6Fourier Transform Ion-Cyclotron Resonance......................................... 747
9.2.3.7Orbitrap MS............................................................................................. 749
9.2.4Detectors................................................................................................................. 750
9.2.4.1Electron Multiplier.................................................................................. 750
9.2.4.2Faraday Cup............................................................................................ 753
9.2.4.3Array Detectors....................................................................................... 754
9.3 Ion Mobility Spectrometry................................................................................................... 755
9.3.1 Handheld DMS JUNO® Chemical Trace Vapor Point Detector............................. 756
9.3.2 Excellims HPIMS-LC System................................................................................ 757

9.3.3 Photonis Ion Mobility Spectrometer Engine.......................................................... 757
9.3.4 SYNAPT G2-S Multistage MS System Incorporating
the TriWAVE Ion Mobility Stage........................................................................... 758
Problems......................................................................................................................................... 760
Bibliography.................................................................................................................................... 761
Chapter 10
Mass Spectrometry II: Spectral Interpretation and Applications................................................... 763
10.1 Interpretation of Mass Spectra: Structural Determination of Simple Molecules................ 763
10.1.1 Molecular Ion and Fragmentation Patterns............................................................ 766
10.1.2 Nitrogen Rule.......................................................................................................... 769
10.1.3 Molecular Formulas and Isotopic Abundances...................................................... 769
10.1.3.1 Counting Carbon Atoms......................................................................... 770
10.1.3.2 Counting Carbon, Nitrogen, and Sulfur Atoms...................................... 771
10.1.3.3 Counting Oxygen Atoms......................................................................... 772
10.1.4 Compounds with Heteroatoms................................................................................ 773
10.1.5 Halogen Isotopic Clusters....................................................................................... 775
10.1.6 Rings Plus Double Bonds....................................................................................... 778
10.1.7 Common Mass Losses on Fragmentation............................................................... 778
10.2 Mass Spectral Interpretation: Some Examples.................................................................... 780
10.2.1 Mass Spectra of Hydrocarbons............................................................................... 782
10.2.2 Mass Spectra of Other Organic Compound Classes............................................... 787
10.2.2.1Alcohols.................................................................................................. 788
10.2.2.2Ethers....................................................................................................... 791
10.2.2.3 Ketones and Aldehydes........................................................................... 791


xiv

Contents

10.2.2.4 Carboxylic Acids and Esters................................................................... 794
10.2.3 Compounds Containing Heteroatoms..................................................................... 794
10.2.3.1 Nitrogen-Containing Compounds........................................................... 795
10.2.3.2 Sulfur-Containing Compounds............................................................... 797
10.3 Applications of Molecular MS............................................................................................. 798
10.3.1 High-Resolution Mass Spectrometry...................................................................... 799
10.3.1.1 Achieving Higher Mass Accuracy (but Not Resolution)
from Low-Resolution MS Instruments...................................................800
10.3.1.2 Improving the Quantitation Accuracy of Isotope Ratios
from Low-Resolution MS Instrument Data Files.................................... 801
10.3.2 Quantitative Analysis of Compounds and Mixtures..............................................802
10.3.3 Protein-Sequencing Analysis (Proteomics)............................................................805
10.3.4 Gas Analysis...........................................................................................................806
10.3.5 Environmental Applications...................................................................................807
10.3.6 Other Applications of Molecular MS.....................................................................807
10.3.7 Limitations of Molecular MS.................................................................................809
10.4 Atomic MS...........................................................................................................................809
10.4.1 ICP-MS................................................................................................................... 810
10.4.2 Applications of Atomic MS.................................................................................... 813
10.4.2.1 Geological and Materials Characterization Applications....................... 815
10.4.2.2 Speciation by Coupled Chromatography-ICP-MS.................................. 818
10.4.2.3 Applications in Food Chemistry, Environmental Chemistry,
Biochemistry, Clinical Chemistry, and Medicine................................... 819
10.4.2.4 Coupled Elemental Analysis MS............................................................ 822
10.4.3 Interferences in Atomic MS.................................................................................... 822
10.4.3.1 Matrix Effects......................................................................................... 823
10.4.3.2 Spectral (Isobaric) Interferences............................................................. 825
10.4.4 Instrumental Approaches to Eliminating Interferences......................................... 827
10.4.4.1 High-Resolution ICP-MS (HR-ICP-MS)................................................. 827
10.4.4.2 Collision and Reaction Cells................................................................... 827

10.4.4.3 MS/MS Interference Removal................................................................ 829
10.4.5 Limitations of Atomic MS...................................................................................... 831
Problems......................................................................................................................................... 832
10.AAppendix..............................................................................................................................840
Bibliography.................................................................................................................................... 842
Chapter 11
Principles of Chromatography........................................................................................................ 845
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.8
11.9
11.10

Introduction to Chromatography.......................................................................................... 845
What Is the Chromatographic Process?...............................................................................846
Chromatography in More than One Dimension..................................................................848
Visualization of the Chromatographic Process at the Molecular Level: Analogy to
“People on a Moving Belt Slideway”................................................................................... 849
Digression on the Central Role of Silicon–Oxygen Compounds in Chromatography........ 853
Basic Equations Describing Chromatographic Separations................................................ 856
How Do Column Variables Affect Efficiency (Plate Height)?............................................. 859
Practical Optimization of Chromatographic Separations.................................................... 862
Extra-Column Band Broadening Effects............................................................................. 863
Qualitative Chromatography: Analyte Identification..........................................................864

Contents

xv

11.11 Quantitative Measurements in Chromatography................................................................. 865
11.11.1 Peak Area or Peak Height: What Is Best for Quantitation?.................................... 865
11.11.2 Calibration with an External Standard...................................................................866
11.11.3 Calibration with an Internal Standard.................................................................... 867
11.12 Examples of Chromatographic Calculations....................................................................... 868
Problems......................................................................................................................................... 870
Bibliography.................................................................................................................................... 872
Chapter 12
Gas Chromatography...................................................................................................................... 873
12.1 Historical Development of GC: The First Chromatographic Instrumentation.................... 873
12.2 Advances in GC Leading to Present-Day Instrumentation.................................................. 874
12.3 GC Instrument Component Design (Injectors).................................................................... 876
12.3.1Syringes.................................................................................................................. 876
12.3.2Autosamplers.......................................................................................................... 876
12.3.3SPME...................................................................................................................... 877
12.3.4 Split Injections........................................................................................................ 878
12.3.5 Splitless Injections.................................................................................................. 879
12.4 GC Instrument Component Design (the Column)............................................................... 880
12.4.1 Column Stationary Phase........................................................................................ 880
12.4.2 Selecting a Stationary Phase for an Application.....................................................884
12.4.3 Effects of Mobile Phase Choice and Flow Parameters........................................... 886
12.5 GC Instrument Operation (Column Dimensions and Elution Values)................................. 887
12.6 GC Instrument Operation (Column Temperature and Elution Values)................................ 888
12.7 GC Instrument Component Design (Detectors)................................................................... 894
12.7.1TCD........................................................................................................................ 896

12.7.1.1 TCD Characteristics................................................................................ 896
12.7.2FID.......................................................................................................................... 897
12.7.2.1 FID Characteristics................................................................................. 897
12.7.3ECD........................................................................................................................ 898
12.7.3.1 ECD Characteristics................................................................................ 898
12.7.4ELCD......................................................................................................................900
12.7.4.1 ELCD Characteristics.............................................................................900
12.7.5SP-FPD...................................................................................................................900
12.7.5.1 SP-FPD Characteristics...........................................................................900
12.7.6SCD......................................................................................................................... 901
12.7.6.1 SCD Characteristics................................................................................ 901
12.7.7NPD........................................................................................................................ 901
12.7.7.1 NPD Characteristics................................................................................ 901
12.7.8PID..........................................................................................................................902
12.7.8.1 PID Characteristics.................................................................................902
12.7.9HID.........................................................................................................................902
12.7.9.1 HID Characteristics.................................................................................902
12.7.10AED........................................................................................................................904
12.7.10.1 AED Characteristics...............................................................................904
12.8 Hyphenated GC Techniques (GC-MS, GC-IR, GC-GC, or 2D GC)...................................905
12.8.1GC-MS....................................................................................................................905
12.8.2 GC-IR Spectrometry...............................................................................................908


xvi

Contents

12.8.3 Comprehensive 2D Gas Chromatography (GC × GC or GC2)...............................909
12.9 Retention Indices (A Generalization of Relative Rt Information)........................................ 911

12.10 Scope of GC Analyses......................................................................................................... 912
12.10.1 GC Behavior of Organic Compound Classes......................................................... 913
12.10.2 Derivatization of Difficult Analytes to Improve GC Elution Behavior.................. 913
12.10.3 Gas Analysis by GC................................................................................................ 914
12.10.4 Limitations of GC................................................................................................... 915
Problems......................................................................................................................................... 915
12.A Appendix: GC Internet Web Resources............................................................................... 918
Bibliography.................................................................................................................................... 919
Chapter 13
Chromatography with Liquid Mobile Phases................................................................................. 921
13.1 High-Performance Liquid Chromatography........................................................................ 921
13.1.1 HPLC Column and Stationary Phases.................................................................... 922
13.1.1.1 Support Particle Considerations..............................................................924
13.1.1.2 Stationary-Phase Considerations.............................................................926
13.1.1.3 Chiral Phases for Separation of Enantiomers......................................... 927
13.1.2 Effects on Separation of Composition of the Mobile Phase...................................928
13.1.2.1 New HPLC-Phase Combinations for Assays of Very
Polar Biomolecules.................................................................................. 929
13.1.2.2 Ion-Exchange Chromatography.............................................................. 930
13.1.2.3 Hydrophilic Interaction Liquid Chromatography................................... 930
13.1.2.4 Polar-Embedded Long Organic Chains on Silica................................... 930
13.1.2.5 Polar-Endcapped Short Hydrocarbon Chains on Silica.......................... 930
13.1.3 Design and Operation of an HPLC Instrument...................................................... 931
13.1.4 HPLC Detector Design and Operation................................................................... 934
13.1.4.1 Refractive Index Detector....................................................................... 934
13.1.4.2 Evaporative Light Scattering Detector.................................................... 935
13.1.4.3 UV/VIS Absorption Detectors................................................................ 938
13.1.4.4 Fluorescence Detector.............................................................................940
13.1.4.5 Electrochemical Detectors...................................................................... 942
13.1.4.6 Conductometric Detector........................................................................ 945

13.1.4.7 Charge Detector (QD) [Thermo Scientific].............................................946
13.1.4.8 Summary Comparison of Six Major HPLC Detectors........................... 947
13.1.5 Derivatization in HPLC.......................................................................................... 947
13.1.6 Hyphenated Techniques in HPLC..........................................................................948
13.1.6.1 Interfacing HPLC to Mass Spectrometry............................................... 949
13.1.7 Applications of HPLC............................................................................................. 954
13.1.7.1 Biochemical Applications in Proteomics................................................ 955
13.2 Chromatography of Ions Dissolved in Liquids....................................................................960
13.2.1 Ion Chromatography............................................................................................... 963
13.2.1.1 Single-Column IC................................................................................... 967
13.2.1.2 Indirect Detection in IC.......................................................................... 968
13.3 Affinity Chromatography..................................................................................................... 968
13.4 Size-Exclusion Chromatography.......................................................................................... 970
13.5 Supercritical Fluid Chromatography................................................................................... 972
13.5.1 Operating Conditions.............................................................................................. 973
13.5.2 Effect of Pressure.................................................................................................... 973


Contents

xvii

13.5.3 Stationary Phases.................................................................................................... 973
13.5.4 Mobile Phases......................................................................................................... 973
13.5.5Detectors................................................................................................................. 974
13.5.6 SFC versus Other Column Methods....................................................................... 974
13.5.7Applications............................................................................................................ 975
13.5.8 Ultra Performance Convergence Chromatography: A New Synthesis................... 975
13.6Electrophoresis..................................................................................................................... 976
13.6.1 Capillary Zone Electrophoresis (CZE)................................................................... 976

13.6.2 Sample Injection in CZE......................................................................................... 982
13.6.3 Detection in CZE.................................................................................................... 984
13.6.4 Modes of CE........................................................................................................... 984
13.6.4.1CZE......................................................................................................... 985
13.6.4.2 Capillary Gel Electrophoresis................................................................. 985
13.6.4.3 Capillary Isoelectric Focusing................................................................ 986
13.6.5 Capillary Electrochromatography.......................................................................... 988
13.6.5.1 Micellar Electrokinetic Capillary Chromatography............................... 989
13.7 Planar Chromatography and Planar Electrophoresis........................................................... 991
13.7.1 Thin-Layer Chromatography.................................................................................. 991
13.7.1.1 Parallel 1D TLC Separations.................................................................. 991
13.7.1.2 Detection in TLC.................................................................................... 993
13.7.1.3 2D Separations Using TLC (2D-TLC)....................................................994
13.7.2 Planar Electrophoresis on Slab Gels.......................................................................994
13.7.2.1 1D Planar Gel Electrophoresis................................................................994
13.7.2.2 2D Planar Gel Electrophoresis................................................................ 995
Problems and Exercises..................................................................................................................996
13.A Appendix LC/CE/TLC Internet Web Resources................................................................. 998
Bibliography....................................................................................................................................999

Chapter 14
Surface Analysis........................................................................................................................... 1001
14.1Introduction........................................................................................................................ 1001
14.2 Electron Spectroscopy Techniques.................................................................................... 1002
14.2.1 X-Ray Photoelectron Spectroscopy......................................................................1004
14.2.1.1 Instrumentation for XPS....................................................................... 1005
14.2.1.2 Sample Introduction and Handling for Surface Analysis......................1011
14.2.1.3 Analytical Applications of XPS............................................................ 1013
14.2.2 Auger Electron Spectroscopy............................................................................... 1021
14.2.2.1 Instrumentation for AES....................................................................... 1026

14.2.2.2 Applications of AES.............................................................................. 1027
14.3 Ion Scattering Spectroscopy.............................................................................................. 1031
14.4 Secondary Ion Mass Spectrometry.................................................................................... 1033
14.4.1 Instrumentation for SIMS..................................................................................... 1033
14.4.1.1 Primary Ion Sources.............................................................................. 1034
14.4.1.2 Mass Spectrometers.............................................................................. 1034
14.4.2 Analytical Applications of SIMS.......................................................................... 1036
14.4.2.1 Quantitative Analysis............................................................................ 1036
14.4.2.2 Ion Microprobe Mass Spectrometry..................................................... 1038


xviii

Contents

14.5 Electron Microprobe (Electron Probe Microanalysis)....................................................... 1039
Problems....................................................................................................................................... 1040
Bibliography.................................................................................................................................. 1041

Chapter 15
Electroanalytical Chemistry......................................................................................................... 1043
15.1 Fundamentals of Electrochemistry.................................................................................... 1043
15.2 Electrochemical Cells........................................................................................................ 1045
15.2.1 Line Notation for Cells and Half-Cells................................................................. 1048
15.2.2 Standard Reduction Potentials.............................................................................. 1049
15.2.2.1 Standard Hydrogen Electrode............................................................... 1049
15.2.3 Sign Conventions.................................................................................................. 1052
15.2.4 Nernst Equation.................................................................................................... 1052
15.2.5 Activity Series....................................................................................................... 1054
15.2.6 Reference Electrodes............................................................................................ 1055

15.2.6.1 Saturated Calomel Electrode................................................................. 1056
15.2.6.2 Silver/Silver Chloride Electrode............................................................ 1057
15.2.7 Electrical Double Layer........................................................................................ 1057
15.3 Electroanalytical Methods................................................................................................. 1058
15.3.1Potentiometry........................................................................................................ 1060
15.3.1.1 Indicator Electrodes.............................................................................. 1061
15.3.1.2 Instrumentation for Measuring Potential.............................................. 1069
15.3.1.3 Analytical Applications of Potentiometry............................................. 1072
15.3.2Coulometry........................................................................................................... 1085
15.3.2.1Electrogravimetry................................................................................. 1087
15.3.2.2 Instrumentation for Electrogravimetry and Coulometry...................... 1087
15.3.2.3 Applied Potential................................................................................... 1088
15.3.2.4 Analytical Determinations Using Faraday’s Law................................. 1089
15.3.3 Conductometric Analysis...................................................................................... 1094
15.3.3.1 Instrumentation for Conductivity Measurements.................................. 1097
15.3.3.2 Analytical Applications of Conductometric Measurements................. 1098
15.3.4Polarography..........................................................................................................1101
15.3.4.1 Classical or DC Polarography............................................................... 1103
15.3.4.2 Half-Wave Potential............................................................................... 1107
15.3.4.3 Normal Pulse Polarography.................................................................. 1108
15.3.4.4 Differential Pulse Polarography.............................................................1110
15.3.5Voltammetry..........................................................................................................1113
15.3.5.1 Instrumentation for Voltammetry..........................................................1115
15.3.5.2 Stripping Voltammetry...........................................................................1116
15.3.5.3 pHit Sensor for pH by Cyclic Voltammetry on Carbon.........................1117
15.3.5.4 Applications of Anodic Stripping Voltammetry....................................1119
15.4 Liquid Chromatography Detectors.....................................................................................1119
15.4.1 Voltammetric Detection........................................................................................ 1120
15.4.2 Conductometric Detection.....................................................................................1121
15.5Spectroelectrochemistry.................................................................................................... 1122

15.6 Quartz Crystal Microbalance............................................................................................. 1127
15.6.1 Piezoelectric Effect............................................................................................... 1127
15.6.2 Electrochemical Quartz Crystal Microbalance.................................................... 1129


Contents

xix

Suggested Experiments..................................................................................................................1131
Problems....................................................................................................................................... 1132
15.A Appendix: Selected Standard Reduction Potentials at 25°C.............................................. 1133
Bibliography.................................................................................................................................. 1134
Chapter 16
Thermal Analysis.......................................................................................................................... 1137
16.1Thermogravimetry............................................................................................................. 1139
16.1.1 TGA Instrumentation.............................................................................................1141
16.1.2 Analytical Applications of Thermogravimetry.....................................................1145
16.1.3 Derivative Thermogravimetry...............................................................................1151
16.1.4 Sources of Error in Thermogravimetry.................................................................1151
16.2 Differential Thermal Analysis........................................................................................... 1154
16.2.1 DTA Instrumentation............................................................................................ 1154
16.2.2 Analytical Applications of DTA........................................................................... 1157
16.3 Differential Scanning Calorimetry.................................................................................... 1159
16.3.1 DSC Instrumentation............................................................................................ 1159
16.3.2 Applications of DSC............................................................................................. 1164
16.3.2.1 Pressure DSC........................................................................................ 1166
16.3.2.2 Modulated DSC..................................................................................... 1166
16.4 Hyphenated Techniques......................................................................................................1167
16.4.1 Hyphenated Thermal Methods..............................................................................1167

16.4.2 Evolved Gas Analysis........................................................................................... 1169
16.5 Thermometric Titrimetry....................................................................................................1173
16.5.1 Applications of Thermometric Titrimetry.............................................................1175
16.6 Direct Injection Enthalpimetry...........................................................................................1175
16.7Microcalorimetry................................................................................................................1177
16.7.1 Micro-DSC Instrumentation..................................................................................1178
16.7.2 Applications of Micro-DSC...................................................................................1178
16.7.3 Isothermal Titration Calorimetry..........................................................................1181
16.7.4 Microliter Flow Calorimetry.................................................................................1183
16.8 Thermomechanical Analysis and Dynamic Mechanical Analysis.................................... 1184
16.8.1Instrumentation..................................................................................................... 1186
16.8.1.1 TMA Equipment................................................................................... 1186
16.8.1.2 DMA Equipment................................................................................... 1188
16.8.2 Applications of TMA and DMA............................................................................1189
16.9 Optical Thermal Analysis.................................................................................................. 1194
16.9.1 Heating Microscope.............................................................................................. 1194
16.9.2 Optical Dilatometers............................................................................................. 1195
16.9.3 Optical Thermal Analyzers with Differential Thermal Analysis......................... 1197
16.10Summary............................................................................................................................ 1199
Suggested Experiments.................................................................................................................1200
Problems....................................................................................................................................... 1201
Bibliography.................................................................................................................................. 1204



Preface
Analytical chemistry today is almost entirely instrumental analytical chemistry and it is performed
by many scientists and engineers who are not chemists. Analytical instrumentation is crucial to
research in molecular biology, medicine, geology, food science, materials science, and many other
fields. While it is true that it is no longer necessary to have almost artistic skills to obtain accurate and precise analytical results using instrumentation, the instruments should not be considered

“black boxes” by those using them. The well-known phrase “garbage in, garbage out” holds true
for analytical instrumentation as well as computers. We hope this book serves to provide users of
analytical instrumentation with an understanding of their instruments.
In keeping with the earlier editions of this text, the book is designed for teaching undergraduates and those with no analytical chemistry background how modern analytical instrumentation
works and what the uses and limitations of analytical instrumentation are. Mathematics is kept
to a minimum. No background in calculus, physics, or physical chemistry is required. The major
fields of modern instrumentation are covered, including applications of each type of instrumental
technique. Each chapter includes a discussion of the fundamental principles underlying each technique, detailed descriptions of the instrumentation, and a large number of applications. Each chapter
includes an updated bibliography and problems, and most chapters have suggested experiments
appropriate to the technique.
This edition has been completely updated, revised, and expanded. To achieve this, the previous
approach of having each chapter be self-contained has been abandoned; repetition has been reduced
to a minimum so that more topics could be covered in more detail. The topics of chromatography and mass spectrometry have been greatly expanded, when compared with the sixth edition,
to better reflect the predominance of chromatography and mass spectrometry instrumentation in
modern laboratories. The equally important topic of NMR, expanded in the last edition to focus on
FTNMR, 13C, and 2D NMR spectral interpretation, now includes time domain NMR (relaxometry)
and an overview of low-field, benchtop, and miniature instrumentation. The topic of electron spin
resonance spectroscopy (ESR, EPR) has been added due to the recent availability of small, lowcost ESR instrumentation and its impact on materials characterization and bioanalysis. Chapter 3
has therefore been renamed to reflect the inclusion of ESR/EPR. Forensic science applications have
been added in appropriate chapters.
A unique feature of this text is the combination of instrumental analysis with organic spectral
interpretation (IR, NMR, and MS). The NMR, IR, and MS spectra, all new in the sixth edition,
courtesy of Bio-Rad Laboratories, Informatics Division (IR, NMR), Aldrich Chemical Company
(NMR), Agilent Technologies, Inc., and one of the authors (MS), were obtained on modern instruments to reflect what students will encounter in modern laboratories. Additional NMR spectra have
been provided by Bruker Corporation and picoSpin LLC for the seventh edition. The use of spreadsheets for performing calculations has been introduced with examples. Reflecting the ubiquitous
nature of the Internet, we have included a large number of instrument manufacturers’ websites,
which contain extensive resources for interested students.
Sampling, sample handling, and storage and sample preparation methods are extensively covered,
and modern methods such as accelerated solvent extraction, solid-phase microextraction (SPME),
QuEChERS, and microwave techniques are included. Instrumentation, the analysis of liquids and

solids, and applications of NMR are discussed in detail. A section on hyphenated NMR techniques
is included, along with an expanded section on MRI and advanced imaging. The IR instrumentation
section is focused on FTIR instrumentation. Absorption, emission, and reflectance spectroscopy
are discussed, as is FTIR microscopy. ATR has been expanded. Near-IR instrumentation and
applications are presented, and the topic of chemometrics is introduced. Coverage of Raman
spectroscopy includes resonance Raman, surface-enhanced Raman, and Raman microscopy.
xxi


xxii

Preface

Chemical imaging is described, including confocal Raman imaging. UV and visible spectroscopy
includes innovations such as flow-through sample holders and fiber-optic probes, as well as instruments for analysis of submicroliter volumes and nondestructive analysis for nucleic acid and protein
determinations. UV absorption spectral interpretation for organic molecules is covered in depth.
Applications described include nucleic acid and protein measurements, spectrophotometric titrations, and new applications in forensic chemistry. Nephelometry, turbidimetry, fluorescence, and
phosphorescence are described in detail, including instrumentation and applications. The measurement of color using the CIE system is described with examples.
All major modern atomic absorption and emission techniques and instrumentation are covered,
including new MP-AES and triple quadrupole ICP-MS instruments. The relatively new technique
of laser-induced breakdown spectroscopy (LIBS) has been added to Chapter 7 and is now currently being used on Mars in the Curiosity rover, which landed on the Red Planet in August 2012.
Appendices with FAAS and GFAAS conditions have been added, and the appendix with limits of
detection for all the atomic spectroscopic techniques has been updated from the sixth edition. The
chapter on X-ray has been significantly revised by Dr. Alexander Seyfarth, the new coauthor of the
chapter, to reflect the state of the art in XRF, XRD, and related techniques. Many new graphics have
been added.
Mass spectrometry has been expanded to two chapters and covers both organic and inorganic
MS instrumentation and applications. GC-MS and LC-MS are described along with MSn instruments for organic and inorganic MS, including new triple quad ICP-MS instrumentation. Modern
ionization methods such as electrospray and MALDI are also described. New surface scanning and
ionization sources, such as desorption electrospray ionization (DESI) and laser ablation electrospray ionization (LAESI), and the DART atmospheric pressure ionization source are introduced.

More advanced high-resolution systems, such as the Orbitrap, and long-path time of flight (JEOL
SpiralTOF and LECO Citius-LC and Pegasus GC-HRT) are described. The use of MS peak profile
correction software to improve mass and spectral accuracy from lower resolution MS instrumentation is described. Uses of HRMS receive increased attention. A new section on ion mobility
spectrometry is added, with a discussion of four systems ranging from handheld vapor monitors to
stages enabling characterization of different conformational isomers in top-end proteomics analyzers. Organic mass spectral interpretation is covered with many examples and new spectra. Organic
and inorganic applications focus on speciation using GC-MS, LC-MS, and hyphenated ICP-MS,
with an emphasis on proteomics, biomolecules, and species of environmental interest. Examples
of atomic MS applications using new simultaneous and “triple quad” ICP-MS systems and glow
discharge surface sampling and hydrogen in metals profiling are added.
In the sixth edition, the subject of chromatographic separations and instrumentation was
expanded from one to three chapters containing more than twice as much text, illustrations, exercises, and problems. The first of these chapters covers the nature of the chromatographic process.
A minimum of complex formulas is introduced; instead, extensive description and analogy are
employed to give the student an intuitive grasp of the mechanisms giving rise to separation, resolution, and detection of separated components. In the seventh edition, additional graphics have
been added to clarify the concepts. In line with current practice, GC is treated as a method almost
completely employing open tubular (capillary) columns. New developments such as SPME injection, low-bleed stationary phases, ionic liquid stationary phases, compound-selective detectors, and
especially interfacing to spectrometric detectors and the use of computerized data processing have
been added. So-called hyphenated techniques such as GC-MS, GC-IR, and comprehensive GC-GC
are included, and new sections on retention indices, derivitization to improve detectability and
volatility, and analysis of gases in air or water have been added. The requirements for implementing and instrumentalizing HPLC are developed from the preceding discussion of GC. The student
gains an appreciation of the difficulties that caused this instrumentation to lag behind GC. Once
overcome, liquid chromatographic instrumentation is seen to have wider applicability, especially


Preface

xxiii

in the burgeoning subdisciplines of bioanalysis, proteomics, and genomics. Major new coverage in
the seventh edition addresses the use of superficially porous, core–shell–particle stationary phases,
which enable much higher resolution and faster analysis. Such UHPLC methods now constitute

more than half of the LC methods in operation. Detailed discussions of instrumental design and
the operation of new detectors, such as the charge detector for ion chromatography, the corona discharge detector, pulsed amperometric detector for saccharides, and the evaporative light scattering
detector for spectrally inert analytes have been added. Major sections on the design and operation
of HPLC interfaces to mass spectrometers (ESI and APCI) have been added, and examples of their
use in protein or peptide sequencing and identification are included. Tables of amino acid structures and nomenclature have been included so that students can follow these descriptions. Separate
sections on ion chromatography, affinity chromatography, size exclusion chromatography, and
supercritical fluid chromatography (SFC) have been expanded. The revival of analytical SFC by the
very recent redesign of instrumentation to enable ultra performance convergence chromatography
(UPC2) is introduced, and examples of the improvements it offers are given. Planar and capillary
electrophoresis are described in detail in Chapter 13, despite not being strictly defined as chromatographic methods. Examples are given of the use of capillary electrophoresis with fluorescencederivitization detection to gene sequencing in genomics and of 2D slab-gel, isoelectric focusing/
SDS-PAGE electrophoresis for protein peptide mapping in proteomics. New appendices provide
links to websites containing examples of thousands of chromatographic separations and encourage
the student to learn how to utilize the resources of commercial column vendors to find a solution to
particular separation or measurement problems.
Section 14.2.1 on XPS has been revised to reflect the current state of commercial instrumentation. Spectroelectrochemistry, briefly introduced in Chapter 5, has been expanded upon in Chapter
15, with commercial instrumentation and examples. Probes based on quartz crystal microbalance response are covered. The radical new pH meter design using calibration-free, easily stored,
extremely robust, voltammetric-based probes with surfaces of anthroquinone-bonded multiwalled
carbon nanotubes, introduced in March 2013 by SENOVA Systems, is described.
The important bioanalytical technique of microcalorimetry has been added to Chapter 16,
Thermal Analysis, and TMA and DMA have been greatly expanded, thanks to the excellent materials and invaluable assistance from TA Instruments. Optical thermal instrumentation is now covered
with the assistance of Expert System Solutions, Italy.
While the authors are extremely grateful to the many experts listed in the acknowledgments,
who have provided graphics, technical advice, rewrites, and reviews of various sections, any errors
that are present are entirely the responsibility of the authors.
James W. Robinson
Eileen M. Skelly Frame
George M. Frame II