Preview analytical chemistry for technicians, fourth edition by kenkel, john (2013)

Analytical Chemistry
for Technicians
Fourth Edition

John Kenkel



Analytical
Chemistry
for
Technicians
Fourth Edition



Analytical
Chemistry
for
Technicians
Fourth Edition

John Kenkel

Boca Raton London New York

CRC Press is an imprint of the
Taylor & Francis Group, an informa business


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This book is dedicated to the hundreds of hardworking students
that have passed through my classroom and laboratory over
the past 36 years. Without them, the wonderful career that has

defined my professional life would have been a mere dream.
This book is also dedicated to the precious women in my personal life that
I dearly love—my wife, Lois, and my daughters, Sister Emily, Jeanie, and
Laura. May God bless you and keep you forever in the palm of His hand.

© 2010 Taylor & Francis Group, LLC



Contents
List of Experiments.........................................................................................................................xvii
Preface.............................................................................................................................................xix
Acknowledgments............................................................................................................................xxi
Author........................................................................................................................................... xxiii
Introduction to Laboratory Work....................................................................................................xxv
Chapter 1 Introduction to Analytical Science................................................................................1
1.1
1.2
1.3
1.4
1.5
1.6

1.7

Analytical Science Defined................................................................................1
Classifications of Analysis..................................................................................2
The Sample......................................................................................................... 3
The Analytical Process......................................................................................3
Analytical Technique and Skills........................................................................4

Elementary Statistics.......................................................................................... 5
1.6.1Errors..................................................................................................... 5
1.6.2Definitions............................................................................................. 6
1.6.3 Distribution of Measurements............................................................... 8
1.6.4 Student’s t............................................................................................ 10
1.6.5 Rejection of Data................................................................................. 12
1.6.6 Final Comments on Statistics.............................................................. 13
Precision, Accuracy, and Calibration............................................................... 13

Chapter 2 Sampling and Sample Preparation.............................................................................. 19
2.1Introduction...................................................................................................... 19
2.2 Obtaining the Sample....................................................................................... 19
2.3 Statistics of Sampling.......................................................................................20
2.4 Sample Handling.............................................................................................. 21
2.4.1 Chain of Custody................................................................................. 21
2.4.2 Maintaining Sample Integrity............................................................. 22
2.5 Sample Preparation—Solid Materials.............................................................. 23
2.5.1 Particle Size Reduction....................................................................... 23
2.5.2 Sample Homogenization and Division................................................ 23
2.5.3 Solid–Liquid Extraction......................................................................24
2.5.4 Other Extractions from Solids.............................................................24
2.6 Water Purification and Use...............................................................................25
2.6.1 Purifying Water by Distillation...........................................................25
2.6.2 Purifying Water by Deionization........................................................26
2.7 Total Sample Dissolution and Other Considerations........................................26
2.7.1 Hydrochloric Acid............................................................................... 27
2.7.2 Sulfuric Acid....................................................................................... 27
2.7.3 Nitric Acid...........................................................................................28
2.7.4 Hydrofluoric Acid................................................................................28
2.7.5 Perchloric Acid....................................................................................28

2.7.6 “Aqua Regia”.......................................................................................28
2.7.7 Acetic Acid..........................................................................................28
2.7.8 Ammonium Hydroxide....................................................................... 29
vii


viii

Contents

2.8Fusion............................................................................................................... 30
2.9Sample Preparation: Liquid Samples, Extracts, and Solutions of Solids......... 30
2.9.1 Extraction from Liquid Solutions........................................................ 30
2.9.2 Dilution, Concentration, and Solvent Exchange................................. 32
2.9.3 Sample Stability.................................................................................. 32
2.10 Liquid–Liquid Extraction................................................................................. 32
2.10.1Introduction......................................................................................... 32
2.10.2 The Separatory Funnel........................................................................ 33
2.10.3Theory.................................................................................................34
2.10.4 Calculations Involving Equation 2.2................................................... 35
2.10.5 Calculations Involving Equation 2.3................................................... 36
2.10.6 Calculations Involving a Combination of Equations 2.3 (or 2.7)
and 2.4................................................................................................. 37
2.10.7 Calculation of Percent Extracted (Equation 2.5)................................ 37
2.10.8Evaporators.......................................................................................... 38
2.11 Solid–Liquid Extraction................................................................................... 38
2.12 Distillation of a Mixture of Liquids................................................................. 39
2.13 Reagents Used in Sample Preparation.............................................................. 41
2.14 Labeling and Record Keeping.......................................................................... 41
Chapter 3 Gravimetric Analysis.................................................................................................. 49

3.1Introduction...................................................................................................... 49
3.2 Weight vs. Mass................................................................................................ 49
3.3 The Balance...................................................................................................... 49
3.4 The Desiccator.................................................................................................. 51
3.5 Calibration and Care of Balances..................................................................... 52
3.6 When to Use Which Balance........................................................................... 52
3.7 Details of Gravimetric Methods....................................................................... 53
3.7.1 Physical Separation Methods and Calculations.................................. 53
3.7.1.1 Loss on Drying.................................................................... 55
3.7.1.2 Loss on Ignition................................................................... 55
3.7.1.3 Residue on Ignition.............................................................. 56
3.7.1.4 Insoluble Matter in Reagents............................................... 56
3.7.1.5 Solids in Water and Wastewater.......................................... 56
3.7.1.6 Particle Size by Analytical Sieving..................................... 57
3.7.2 Chemical Alteration/Separation of the Analyte.................................. 58
3.7.3 Gravimetric Factors............................................................................. 59
3.7.4 Using Gravimetric Factors.................................................................. 61
3.8 Experimental Considerations........................................................................... 63
3.8.1 Weighing Bottles................................................................................. 63
3.8.2 Weighing by Difference...................................................................... 63
3.8.3 Isolating and Weighing Precipitates....................................................64
Chapter 4 Introduction to Titrimetric Analysis........................................................................... 73
4.1Introduction...................................................................................................... 73
4.2Terminology..................................................................................................... 73
4.3 Review of Solution Concentration.................................................................... 75
4.3.1Molarity............................................................................................... 75
4.3.2Normality............................................................................................ 77


ix

Contents

4.4

Review of Solution Preparation........................................................................ 79
4.4.1 Solid Solute and Molarity....................................................................80
4.4.2 Solid Solute and Normality................................................................. 81
4.4.3 Solution Preparation by Dilution......................................................... 82
4.5 Stoichiometry of Titration Reactions............................................................... 82
4.6Standardization.................................................................................................84
4.6.1 Standardization Using a Standard Solution........................................84
4.6.2 Standardization Using a Primary Standard........................................ 86
4.6.3Titer..................................................................................................... 88
4.7 Percentage Analyte Calculations...................................................................... 88
4.8 Volumetric Glassware....................................................................................... 91
4.8.1 Volumetric Flask................................................................................. 91
4.8.2Pipet.....................................................................................................94
4.8.3Buret.................................................................................................... 98
4.8.4 Cleaning and Storing Procedures...................................................... 100
4.9 Pipetters, Automatic Titrators, and Other Devices........................................ 100
4.9.1Pipetters............................................................................................. 100
4.9.2 Bottle-Top Dispensers....................................................................... 102
4.9.3 Digital Burets and Automatic Titrators............................................. 102
4.10 Calibration of Glassware and Devices........................................................... 103
4.11 Analytical Technique...................................................................................... 103
Chapter 5 Applications of Titrimetric Analysis......................................................................... 113
5.1Introduction.................................................................................................... 113
5.2 Acid–Base Titrations and Titration Curves.................................................... 113
5.2.1 Titration of Hydrochloric Acid.......................................................... 113

5.2.2 Titration of Weak Monoprotic Acids................................................ 115
5.2.3 Titration of Monobasic Strong and Weak Bases............................... 116
5.2.4 Equivalence Point Detection............................................................. 116
5.2.5 Titration of Polyprotic Acids: Sulfuric Acid and Phosphoric
Acid............................................................................................ 118
5.2.6 Titration of Potassium Biphthalate.................................................... 121
5.2.7 Titration of Tris-(Hydroxymethyl)Amino Methane.......................... 122
5.2.8 Titration of Sodium Carbonate.......................................................... 122
5.3 Examples of Acid/Base Determinations........................................................ 123
5.3.1 Alkalinity of Water or Wastewater.................................................... 124
5.3.2 Back Titration Applications.............................................................. 124
5.3.3Indirect Titration Applications.......................................................... 126
5.4 Other Acid/Base Applications........................................................................ 127
5.5 Buffer Solution Applications.......................................................................... 127
5.5.1 Conjugate Acids and Bases............................................................... 128
5.5.2 Henderson–Hasselbalch Equation..................................................... 129
5.6 Complex Ion Formation Reactions................................................................. 133
5.6.1Introduction....................................................................................... 133
5.6.2 Complex Ion Terminology................................................................ 133
5.6.3 EDTA and Water Hardness............................................................... 135
5.6.4 Expressing Concentration Using Parts per Million.......................... 138
5.6.4.1 Solution Preparation.......................................................... 139
5.6.5 Water Hardness Calculations............................................................ 141
5.6.6 Other Uses of EDTA Titrations......................................................... 143


x

Contents

5.7

5.8

Oxidation–Reduction Reactions..................................................................... 144
5.7.1 Review of Basic Concepts and Terminology.................................... 144
5.7.2 The Ion-Electron Method for Balancing Equations.......................... 147
5.7.3 Analytical Calculations..................................................................... 148
5.7.4Applications....................................................................................... 150
5.7.4.1 Potassium Permanganate................................................... 150
5.7.4.2 Iodometry: An Indirect Method........................................ 150
5.7.4.3 Prereduction and Preoxidation.......................................... 152
Other Examples.............................................................................................. 152

Chapter 6 Introduction to Instrumental Analysis...................................................................... 165
6.1
6.2
6.3

6.4
6.5

6.6

6.7

Review of the Analytical Process................................................................... 165
Instrumental Analysis Methods..................................................................... 166
Basics of Instrumental Measurement............................................................. 167
6.3.1 Sensors, Signal Processors, Readouts, and Power Supplies.............. 168

6.3.2 Calibration of an Analytical Instrument........................................... 168
6.3.3 Mathematics of Linear Relationships................................................ 170
6.3.4 Method of Least Squares................................................................... 171
6.3.5 The Correlation Coefficient............................................................... 172
Preparation of Standards................................................................................ 172
Blanks and Controls....................................................................................... 173
6.5.1 Reagent Blanks.................................................................................. 173
6.5.2 Sample Blanks................................................................................... 174
6.5.3Controls............................................................................................. 174
Post-Run Calculations in Instrumental Analysis............................................ 174
6.6.1 Calculation of ppm Analyte in a Solution Given Mass and
Volume Data...................................................................................... 175
6.6.2 Calculation of ppm Analyte in a Solid Sample Given Mass Data......... 175
6.6.3 Calculation of the Mass of Analyte Found in an Extract.................. 175
6.6.4 Calculation of ppm Analyte in a Liquid or Solid That Was
Extracted........................................................................................... 176
6.6.5 Calculation When a Dilution Is Involved.......................................... 176
Laboratory Data Acquisition and Information Management......................... 178
6.7.1 Data Acquisition................................................................................ 178
6.7.2 Laboratory Information Management............................................... 179

Chapter 7 Introduction to Spectrochemical Methods................................................................ 185
7.1Introduction.................................................................................................... 185
7.2 Characterizing Light....................................................................................... 185
7.2.1 Wavelength, Speed, Frequency, Energy, and Wavenumber.............. 186
7.3 The Electromagnetic Spectrum...................................................................... 189
7.4Refractometry................................................................................................. 190
7.5 Absorption and Emission of Light................................................................. 193
7.5.1 Brief Summary.................................................................................. 193
7.5.2 Atoms vs. Molecules and Complex Ions........................................... 196

7.5.3 Absorption Spectra............................................................................ 197
7.5.4 Light Emission.................................................................................. 201
7.6 Absorbance, Transmittance, and Beer’s Law.................................................202
7.7 Effect of Concentration on Spectra................................................................207


Contents

xi

Chapter 8 UV-Vis and IR Molecular Spectrometry................................................................... 215
8.1Review............................................................................................................ 215
8.2 UV-Vis Instrumentation................................................................................. 215
8.2.1Sources.............................................................................................. 215
8.2.1.1 Tungsten Filament Lamp................................................... 215
8.2.1.2 Deuterium Lamp................................................................ 216
8.2.1.3 Xenon Arc Lamp............................................................... 216
8.2.2 Wavelength Selection........................................................................ 216
8.2.2.1 Absorption Filters.............................................................. 217
8.2.2.2Monochromators................................................................ 217
8.2.3 Sample Compartment........................................................................ 220
8.2.3.1 Single-Beam Spectrophotometer....................................... 220
8.2.3.2 Beam Splitting and Chopping........................................... 221
8.2.3.3 Double-Beam Designs....................................................... 222
8.2.3.4 Diode Array Design........................................................... 223
8.2.3.5Summary........................................................................... 225
8.2.4Detectors........................................................................................... 226
8.2.4.1 Photomultiplier Tube......................................................... 226
8.2.4.2Photodiodes....................................................................... 228
8.3 Cuvette Selection and Handling..................................................................... 228

8.4 Interferences, Deviations, Maintenance, and Troubleshooting...................... 229
8.4.1Interferences...................................................................................... 229
8.4.2Deviations.......................................................................................... 229
8.4.3Maintenance...................................................................................... 230
8.4.4Troubleshooting................................................................................. 230
8.5Fluorometry.................................................................................................... 231
8.6 Introduction to IR Spectrometry.................................................................... 233
8.7 IR Instrumentation......................................................................................... 234
8.8Sampling......................................................................................................... 235
8.8.1 Liquid Sampling................................................................................ 235
8.9 Solid Sampling...............................................................................................240
8.9.1 Solution Prepared and Placed in a Liquid Sampling Cell.................240
8.9.2 Thin Film Formed by Solvent Evaporation.......................................240
8.9.3 KBr Pellet..........................................................................................240
8.9.4 Nujol Mull......................................................................................... 242
8.9.5 Reflectance Methods......................................................................... 242
8.9.5.1 Specular Reflectance......................................................... 242
8.9.5.2 Internal Reflectance........................................................... 242
8.9.5.3 Diffuse Reflectance...........................................................244
8.9.6 Gas Sampling....................................................................................244
8.10 Basic IR Spectra Interpretation......................................................................244
8.11 Quantitative Analysis..................................................................................... 247
Chapter 9 Atomic Spectroscopy................................................................................................ 259
9.1 Review and Comparisons............................................................................... 259
9.2Brief Summary of Techniques and Instrument Designs................................260
9.3 Flame Atomic Absorption.............................................................................. 262
9.3.1Flames and Flame Processes............................................................ 262
9.3.2 Spectral Line Sources....................................................................... 263

xii

Contents

9.3.2.1 Hollow Cathode Lamp.......................................................264
9.3.2.2 Electrodeless Discharge Lamp.......................................... 265
9.3.3 Premix Burner................................................................................... 265
9.3.4 Optical Path....................................................................................... 267
9.3.5Practical Matters and Applications................................................... 268
9.3.5.1 Slits and Spectral Lines..................................................... 268
9.3.5.2Linear and Nonlinear Standard Curves............................. 269
9.3.5.3Hollow Cathode Lamp Current......................................... 271
9.3.5.4Lamp Alignment................................................................ 271
9.3.5.5Aspiration Rate.................................................................. 271
9.3.5.6Burner Head Position......................................................... 271
9.3.5.7Fuel and Oxidant Sources and Flow Rates........................ 271
9.3.6Interferences...................................................................................... 271
9.3.6.1Chemical Interferences...................................................... 272
9.3.6.2Spectral Interferences........................................................ 273
9.3.7Safety and Maintenance.................................................................... 274
9.4Graphite Furnace Atomic Absorption............................................................ 275
9.4.1General Description.......................................................................... 275
9.4.2Advantages and Disadvantages......................................................... 277
9.5Inductively Coupled Plasma........................................................................... 278
9.6Miscellaneous Atomic Techniques................................................................. 281
9.6.1Flame Photometry............................................................................. 281
9.6.2Cold Vapor Mercury.......................................................................... 282
9.6.3Hydride Generation........................................................................... 282
9.6.4Spark Emission.................................................................................. 282
9.6.5Atomic Fluorescence......................................................................... 282

9.7Summary of Atomic Techniques.................................................................... 282
Chapter 10 Introduction to Chromatography............................................................................... 291
10.1Introduction.................................................................................................... 291
10.2Chromatography............................................................................................. 291
10.3 “Types” of Chromatography........................................................................... 292
10.3.1 Partition Chromatography................................................................. 292
10.3.2 Adsorption Chromatography............................................................. 293
10.3.3 Ion-Exchange Chromatography........................................................ 294
10.3.4 Size Exclusion Chromatography....................................................... 295
10.4 Chromatography Configurations.................................................................... 295
10.4.1 Paper and Thin-Layer Chromatography........................................... 296
10.4.2 Classical Open-Column Chromatography........................................ 298
10.4.3 Instrumental Chromatography.......................................................... 301
10.4.4 Instrumental Chromatogram............................................................. 301
10.4.5 Quantitative Analysis with GC and HPLC....................................... 305
10.5Electrophoresis...............................................................................................306
Chapter 11 Gas Chromatography................................................................................................ 311
11.1Overview........................................................................................................ 311
11.2 Vapor Pressure and Solubility........................................................................ 311
11.3Instrument Components................................................................................. 312
11.4 Sample Injection............................................................................................. 314


Contents

xiii

11.5 Column Details............................................................................................... 316
11.5.1 Instrument Logistics.......................................................................... 316
11.5.2 Packed, Open Tubular, and Preparative Columns............................. 317

11.5.3 The Nature and Selection of the Stationary Phase............................ 318
11.5.4 Column Temperature......................................................................... 319
11.5.5 Carrier Gas Flow Rate...................................................................... 320
11.6Detectors......................................................................................................... 321
11.6.1Flame Ionization Detector (FID)...................................................... 321
11.6.2Thermal Conductivity Detector (TCD)............................................. 322
11.6.3Electron Capture Detector (ECD)..................................................... 323
11.6.4Nitrogen/Phosphorus Detector (NPD).............................................. 324
11.6.5Flame Photometric Detector (FPD).................................................. 324
11.6.6 Electrolytic Conductivity (Hall Detector)......................................... 324
11.6.7 Gas Chromatography–Mass Spectrometry (GC-MS)....................... 324
11.6.8 Photoionization Detector (PID)......................................................... 325
11.7 Qualitative Analysis....................................................................................... 325
11.8 Quantitative Analysis..................................................................................... 326
11.8.1 Quantitation Methods........................................................................ 326
11.8.2 Response Factor Method................................................................... 326
11.8.3 Internal Standard Method................................................................. 327
11.8.4 Standard Additions Method.............................................................. 328
11.9Troubleshooting.............................................................................................. 329
11.9.1 Diminished Peak Size....................................................................... 329
11.9.2 Unsymmetrical Peak Shapes............................................................. 329
11.9.3 Altered Retention Times................................................................... 330
11.9.4 Baseline Drift.................................................................................... 330
11.9.5 Baseline Perturbations....................................................................... 330
11.9.6 Appearance of Unexpected Peaks..................................................... 330
Chapter 12 High-Performance Liquid Chromatography and Electrophoresis............................ 341
12.1Introduction.................................................................................................... 341
12.1.1 Summary of Method......................................................................... 341
12.1.2 Comparisons with GC....................................................................... 341
12.2 Mobile Phase Considerations......................................................................... 342

12.3 Solvent Delivery.............................................................................................344
12.3.1Pumps................................................................................................344
12.3.2 Gradient vs. Isocratic Elution............................................................ 345
12.4 Sample Injection.............................................................................................346
12.5 Column Selection...........................................................................................348
12.5.1 Normal Phase Columns.....................................................................348
12.5.2 Reverse-Phase Columns....................................................................348
12.5.3 Adsorption Columns......................................................................... 349
12.5.4 Ion Exchange and Size Exclusion Columns...................................... 349
12.5.5 The Size of the Stationary Phase Particles........................................ 349
12.5.6 Column Selection.............................................................................. 349
12.6Detectors......................................................................................................... 350
12.6.1 UV Absorption.................................................................................. 350
12.6.2 Diode Array....................................................................................... 351
12.6.3Fluorescence...................................................................................... 351
12.6.4 Refractive Index................................................................................ 353


xiv

Contents

12.6.5Electrochemical................................................................................. 354
12.6.5.1Conductivity....................................................................... 354
12.6.5.2Amperometric.................................................................... 354
12.7 Qualitative and Quantitative Analysis............................................................ 355
12.8Troubleshooting.............................................................................................. 356
12.8.1 Unusually High Pressure................................................................... 356
12.8.2 Unusually Low Pressure.................................................................... 356
12.8.2.1 System Leaks..................................................................... 356

12.8.2.2 Air Bubbles........................................................................ 357
12.8.2.3 Column “Channeling”....................................................... 357
12.8.2.4 Decreased Retention Time................................................ 357
12.8.2.5 Baseline Drift.................................................................... 357
12.9Electrophoresis............................................................................................... 357
12.9.1Introduction....................................................................................... 357
12.9.2 Capillary Electrophoresis.................................................................. 359
12.9.2.1 Electroosmotic Flow.......................................................... 361
12.9.2.2 Sample Introduction.......................................................... 361
12.9.2.3 Analyte Detection.............................................................. 361
Chapter 13 Mass Spectrometry.................................................................................................... 371
13.1 Basic Principles.............................................................................................. 371
13.2 Sample Inlet Systems and Ion Sources........................................................... 372
13.3 Mass Analyzers.............................................................................................. 373
13.4 The Ion Detector............................................................................................. 376
13.5 Mass Spectra................................................................................................... 377
13.6ICP-MS........................................................................................................... 378
13.7GC-MS........................................................................................................... 378
13.8LC-MS............................................................................................................ 380
13.9 Tandem Mass Spectrometry........................................................................... 381
Chapter 14 Electroanalytical Methods........................................................................................ 387
14.1Introduction.................................................................................................... 387
14.2 Transfer Tendencies: Standard Reduction Potentials..................................... 391
14.3 Determination of Overall Redox Reaction Tendency: E°cell............................ 393
14.4 The Nernst Equation....................................................................................... 394
14.5Potentiometry................................................................................................. 396
14.5.1 Reference Electrodes......................................................................... 396
14.5.1.1 The Saturated Calomel Reference Electrode (SCE).......... 396
14.5.1.2 The Silver–Silver Chloride Electrode................................ 398
14.5.2 Indicator Electrodes.......................................................................... 399

14.5.2.1 The pH Electrode............................................................... 399
14.5.3 Combination Electrodes....................................................................400
14.5.3.1 The Combination pH Electrode.........................................400
14.5.3.2 Ion-Selective Electrodes.................................................... 401
14.5.4 Other Details of Electrode Design....................................................403
14.5.5 Care and Maintenance of Electrodes................................................403
14.5.6 Potentiometric Titrations...................................................................404
14.6 Voltammetry and Amperometry....................................................................405
14.6.1Voltammetry......................................................................................405


Contents

xv

14.6.2Amperometry....................................................................................406
14.7 Karl Fischer Titration.....................................................................................406
14.7.1 End Point Detection..........................................................................406
14.7.2 Elimination of Extraneous Water......................................................407
14.7.3 The Volumetric Method....................................................................407
14.7.4 The Coulometric Method..................................................................409
Chapter 15 Miscellaneous Instrumental Techniques................................................................... 417
15.1 X-Ray Methods............................................................................................... 417
15.1.1Introduction....................................................................................... 417
15.1.2 X-Ray Diffraction Spectroscopy....................................................... 418
15.1.3 X-Ray Fluorescence Spectroscopy.................................................... 421
15.1.4Applications....................................................................................... 421
15.1.5 Safety Issues Concerning X-Rays..................................................... 422
15.2 Nuclear Magnetic Resonance Spectroscopy.................................................. 422
15.2.1Introduction....................................................................................... 422

15.2.2Instrumentation................................................................................. 423
15.2.3 The NMR Spectrum.......................................................................... 425
15.2.3.1 Chemical Shifts................................................................. 425
15.2.3.2 Peak Splitting and Integration........................................... 427
15.2.4 Solvents and Solution Concentration................................................. 428
15.2.5 Analytical Uses................................................................................. 428
15.3Viscosity......................................................................................................... 428
15.3.1Introduction....................................................................................... 428
15.3.2Definitions......................................................................................... 429
15.3.3 Temperature Dependence.................................................................. 430
15.3.4 Capillary Viscometry........................................................................ 430
15.3.5 Rotational Viscometry...................................................................... 433
15.4 Thermal Analysis........................................................................................... 434
15.4.1Introduction....................................................................................... 434
15.4.2 DTA and DSC................................................................................... 434
15.4.3 DSC Instrumentation......................................................................... 436
15.4.4 Applications of DSC.......................................................................... 437
15.5 Optical Rotation............................................................................................. 437
Appendix 1: Formulas for Solution Concentration and Preparation Calculations................ 443
Appendix 2: T
 he Language of Quality Assurance and Good Laboratory Practice
(GLP) Laws: A Glossary........................................................................................ 447
Appendix 3: S
 ignificant Figure Rules......................................................................................... 451
Appendix 4: Answers to Questions and Problems..................................................................... 453



List of Experiments
Experiment 1:  Assuring the Quality of Weight Measurements...................................................... 14

Experiment 2:  Weight Uniformity of Dosing Units....................................................................... 15
Experiment 3: A Study of the Dissolving Properties of Water, Some Common Organic
Liquids, and Laboratory Acids............................................................................... 42
Experiment 4:  Loss on Drying....................................................................................................... 64
Experiment 5:  Particle Sizing........................................................................................................ 65
Experiment 6:  The Determination of Salt in a Salt–Sand Mixture................................................ 65
Experiment 7:  The Gravimetric Determination of Sulfate in a Commercial Unknown................ 65
Experiment 8:  High-Precision Glassware: A Calibration Experiment........................................ 104
Experiment 9:  Preparation and Standardization of HCl and NaOH Solutions............................ 106
Experiment 10: Titrimetric Analysis of a Commercial Soda Ash Unknown for Sodium
Carbonate............................................................................................................. 152
Experiment 11:  Titrimetric Analysis of a Commercial KHP Unknown for KHP.......................... 152
Experiment 12:  EDTA Titrations................................................................................................... 153
Experiment 13:  Plotting a Standard Curve Using Excel Spreadsheet Software (Version 2010)........179
Experiment 14:  Percentage of Sugar in Soft Drinks by Refractometry......................................... 207
Experiment 15:  Colorimetric Analysis of Prepared and/or Real Water Samples for Iron............. 207
Experiment 16: Design an Experiment: A Study of the Effect of pH on the Analysis of
Water Samples for Iron........................................................................................208
Experiment 17: Design an Experiment: Determining the Concentration at Which a Beer’s
Law Plot Becomes Nonlinear............................................................................... 208
Experiment 18:  The Determination of Phosphorus in Environmental Water................................ 208
Experiment 19:  Spectrophotometric Analysis of a Prepared Sample for Toluene......................... 248
Experiment 20:  Extraction of Iodine with Cyclohexane................................................................ 248
Experiment 21:  Determination of Nitrate in Drinking Water by UV Spectrophotometry............. 249
Experiment 22:  Fluorometric Analysis of a Prepared Sample for Riboflavin............................... 249
Experiment 23: Design an Experiment: Determination of Riboflavin in a Vitamin Tablet
Using Fluorometry............................................................................................... 250
Experiment 24:  Quantitative Infrared Analysis of Isopropyl Alcohol in Toluene......................... 250
Experiment 25:  Quantitative Flame Atomic Absorption Analysis of a Prepared Sample............. 284
Experiment 26:  The Analysis of Soil Samples for Iron Using Atomic Absorption....................... 284

Experiment 27: Design an Experiment: A Study to Determine the Optimum pH for the
Extraction Solution for Experiment 26................................................................ 285
Experiment 28:  The Determination of Sodium in Soda Pop......................................................... 285
Experiment 29: Design an Experiment: Sodium in Soda Pop by the Standard Additions
Method................................................................................................................. 286
Experiment 30:  Design an Experiment: Analysis of Fertilizer for Potassium............................... 286
Experiment 31:  Thin-Layer Chromatography Analysis of Cough Syrups for Dyes......................306
Experiment 32:  Thin-Layer Chromatography Analysis of Jelly Beans for Food Coloring........... 307
Experiment 33: A Qualitative Gas Chromatography Analysis of a Prepared Sample................... 330
Experiment 34: The Quantitative Gas Chromatography Analysis of a Prepared Sample
for Toluene by the Internal Standard Method...................................................... 331
Experiment 35: The Determination of Ethanol in Wine by Gas Chromatography and the
Internal Standard Method..................................................................................... 332

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List of Experiments

Experiment 36: Design an Experiment: Determination of Ethanol in Cough Medicine or
Other Pharmaceutical Preparation........................................................................ 333
Experiment 37: A Study of the Effect of the Changing of GC Instrument Parameters on
Resolution............................................................................................................. 333
Experiment 38: The Quantitative Determination of Methyl Paraben in a Prepared Sample by
HPLC.................................................................................................................... 362
Experiment 39: HPLC Determination of Caffeine in Soda Pop.................................................... 363
Experiment 40: Design an Experiment: Dependence of Caffeine Analysis on the pH of the
Mobile Phase........................................................................................................ 364

Experiment 41:  The Analysis of Mouthwash by HPLC: A Research Experiment........................ 364
Experiment 42:  The Determination of 4-Hydroxyacetophenone by Capillary Electrophoresis.... 365
Experiment 43: The Quantitative GC-MS Analysis of a Prepared Sample for Chlorobenzene
by the Internal Standard Method.......................................................................... 382
Experiment 44: GC-MS Determination of Ethylbenzene in Gasoline by Combined Internal
Standard and Standard Additions Methods.......................................................... 382
Experiment 45:  Determination of the pH of Soil Samples............................................................ 409
Experiment 46: Analysis of a Prepared Unknown for Fluoride Using an Ion-Selective
Electrode............................................................................................................... 409
Experiment 47: Design an Experiment: Determination of Fluoride in Toothpaste Using an
Ion-Selective Electrode........................................................................................ 410
Experiment 48: Operation of Metrohm Model 701 Karl Fischer Titrator (for Liquid
Samples)............................................................................................................... 410


Preface
The primary purpose of this text continues to be as a training manual for chemistry-based laboratory technicians. It is designed to emphasize the practical rather than the theorical. The practical
begins with classical quantitative analysis, because this is what instills the mindset of analytical
skill and technique into the students’ psyche, and very practicing scientists should agree that this
is a very important part of a technician’s training. But equally important is what follows this in the
book: a very practical approach to the complex world of the sophisticated electronic instrumentation that a technician will find in common use in the real-world laboratory. My hope is that laboratory supervisors will find that technicians who have utilized this textbook will have an analytical
mindset and a basic understanding of the analytical instrumentation needed for success on the job.
It has been 10 years since the publication of the third edition of Analytical Chemistry for
Technicians. I have taught the sequence of courses that use this text over 20 times since then. Each
time I teach these courses, it seems I have fresh ideas and new developments to discuss with my
students. These have resulted in new drawings for my PowerPoint slides and new (and I hope better)
explanations of what can be complex instrument designs and functions. It is true that my students
have a limited background in chemistry when they come to me, and so I strive to write, draw, and
speak with this in mind.
And now the time has come for the fourth edition. What is new and what has changed? Following

is the list:
• Over 150 new photographs and either new or reworked drawings spanning every chapter
to assist the visual learner.
• A new chapter on mass spectrometry.
• Thirteen new laboratory experiments, including nine “design an experiment” exercises.
• An “Introduction to Laboratory Work” section before Chapter 1 to give students a preview of general laboratory considerations, safety, laboratory notebooks, and instrumental
analysis.
• “Application Notes” in each chapter. A few of these are carryovers of the “Workplace
Scenes” in the third edition, but most are new. The intent is to give students a larger hint of
how specific techniques may be routinely used in the laboratory.
• Calculation summary tables in Chapters 3 and 4.
• Relevant section headings in the end-of-chapter Questions and Problems section to help
better organize the material for students.
• An appendix providing a glossary of quality assurance and good laboratory practice (GLP)
terms.
• More end-of-chapter problems in Chapters 1, 2, 3, 6, and 14 covering statistics, liquid–liquid
extraction, gravimetric analysis, post-run instrumental analysis, and electrode potential.
• More examples of calculations covering liquid–liquid extraction theory and post-run
instrumental analysis in Chapters 2 and 6.
• The topic of refractometry has been moved to Chapter 7 from Chapter 15 since it represents a basic technique involving light.
• The topics of liquid–liquid extraction, solid–liquid extraction, and distillation–deionization
have been moved to Chapter 2 from Chapter 11 as sample and solution preparation techniques rather than analytical separation techniques. Chapter 11 has become Chapter 10 and
is now dedicated to chromatography, and this is reflected in the chapter title “Introduction
to Chromatography.”

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Preface

• The topic of capillary electrophoresis has been moved from the former Chapter 11 to the
new Chapter 12 and expanded.
• Chapter 1 has been expanded to include more information on statistics.
• Expanded end-of-chapter “report”-type questions have been included in Chapters 5, 7, 8, 9,
11, 12, and 14 to give improved guidance to students as to how to answer these questions.
• De-emphasis of the Kjeldahl method in Chapter 5.
• Appendix 1 has been reworked to include the percent unit and deleting standardization and
percentages of analyte formulas.
• The material from the former Chapter 10 (“Other Spectroscopic Methods”) has been
moved to the new mass spectrometry chapter and to a new Chapter 15, “Miscellaneous
Instrumental Technique.”
• Coverage of the mathematical relationships involving wavelength, frequency, energy, and
wavenumber have been retained, but the calculations involving these relationships have
been deleted.
• The first few sections of Chapter 11, “Gas Chromatography,” have been rewritten to reflect
the popularity of capillary columns and to include more information about injectors.
GC-MS coverage has been moved to Chapter 13, “Mass Spectrometry.”
• The chapters on bioanalysis and physical testing methods have been deleted. Approximately
25% of this latter chapter is in the new Chapter 15, “Miscellaneous Instrumental Technique.”
• Coverage of recrystallization has been deleted.
One of the biggest changes is the introduction of an entirely new chapter on mass spectrometry,
Chapter 13, which includes coverage of GC-MS, LC-MS, LC-MS-MS, and ICP-MS. This chapter
follows other chapters on basic quantitative analysis, atomic and molecular spectroscopy, and gas
and liquid chromatography. It comes in the third course in the analytical chemistry sequence at
Southeast Community College, and while the students’ background is far from advanced at that
point, I find that they are well prepared for an illustrated but limited discussion of this important

topic.
What do I mean by illustrated? Reading this text, students will see dozens of new illustrative
drawings and photographs throughout, not just in Chapter 13. I find that most of my students learn
and I can teach best from illustrations. Whether the topic is laboratory glassware, spectrophotometers, gas chromatographs, mass spectrometers, or electrodes, students are visual learners, and all
the drawings and photographs were created by me. I had no outside artist or photographer for this
text. Over the years, I have learned to use the drawing tools in PowerPoint to great advantage. I have
also learned how to use digital photography to great advantage. The drawings and photographs are
exactly as I intended them to appear because I created them. Some were done over the last 10 years
of teaching and others were done as I sat at my desk or laboratory bench the past 2 years and contemplated how best to convey the information in this fourth edition.
From monochromators to capillary columns, from absorption spectra to standard curves, from
titration curves to electrodes, from double-beam spectrophotometers to quadrupole mass analyzers,
and from flame atomic absorption to ICP-MS, there are many new and, I trust, improved illustrations and photographs for students to ponder.
Of course, I am anxious for students to get their hands on this fourth edition and to begin to
peruse its contents. It comes to you after 36 years of practice, and it has evolved considerably since
the first edition appeared in 1988. Good luck to you!
John Kenkel
Southeast Community College

© 2010 Taylor & Francis Group, LLC


Acknowledgments
I am very grateful to Southeast Community College for the professional niche they provided me
starting in 1977 and continuing for a full 36 years. In all that time, I have come to know many students who are hungry to learn about science and to have a career in the field. They were my primary
inspiration year after year.
As always, I am indebted to a number of people who assisted in some direct way during the
development of the manuscript. My editor at CRC Press, Barbara Glunn, offered me the opportunity
and was very friendly and encouraging at every step along the way, especially when I asked if I
could delay the project six months due to a serious family illness.
A number of my colleagues at institutions across the United States served as reviewers on this

project and I appreciate their work very much. They are:









Tracy Holbrook, Cape Fear Community College
Cynthia Peck, Delta College
Michele Mangels, Cincinnati State Technical and Community College
Susan Marine, Miami University Middletown
Charlie Newman, Mount San Antonio College
Onofrio Gaglione, College of Southern Nevada
Kazumasa Lindley, College of Southern Nevada
Renee Madyun, Los Angeles Trade Tech College

I am indebted to my wife, Lois, for her superior proofreading skills. One thing I have learned
during my various writing projects over the years is that many errors seem to creep in unnoticed despite a seemingly thorough review by the author. For this project, Lois’ help was greatly
appreciated.
John Kenkel
Southeast Community College

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Author
John Kenkel is a chemistry instructor at Southeast Community College (SCC) in Lincoln,
Nebraska. Throughout his 36-year career at SCC, he has been directly involved in the education of
chemistry-­based laboratory technicians in a vocational program. He has also been heavily involved
in chemistry-based laboratory technician education on a national level, having served on a number of American Chemical Society (ACS) committees, including the Committee on Technician
Activities and the Coordinating Committee for the Voluntary Industry Standards project. In addition to these, he has served a 5-year term on the ACS Committee on Chemistry in the Two-Year
College, the committee that administers the Two-Year College Chemistry Consortium (2YC3) conferences. He was the general chair of this committee in 1996. He later served a 3-year term on this
committee as the Industrial Sponsor Chair (2006–2008).
Mr. Kenkel has authored several popular textbooks for chemistry-based technician education.
Three editions of Analytical Chemistry for Technicians preceded the current edition, the first published in 1988, the second in 1994, and the third in 2003. In addition, he has authored five other
books: Basic Chemistry Concepts and Exercises, published in 2011, Chemistry: An Industry-Based
Introduction and Chemistry: An Industry-Based Laboratory Manual, both published in 2000–
2001, Analytical Chemistry Refresher Manual, published in 1992, and A Primer on Quality in the
Analytical Laboratory, which was published in 2000. All were published through CRC Press/Lewis
Publishers.
Mr. Kenkel has been the principal investigator for a series of curriculum development project
grants funded by the National Science Foundation’s Advanced Technological Education Program,
from which four of his nine books evolved. He has also authored or coauthored four articles on the
curriculum work in the Journal of Chemical Education and has presented this work at more than
20 conferences.
In 1996, Mr. Kenkel won the prestigious National Responsible Care Catalyst Award for excellence in chemistry teaching sponsored by the Chemical Manufacturer’s Association. He has a master’s degree in chemistry from the University of Texas at Austin (1972) and a bachelor’s degree in
chemistry (1970) from Iowa State University. His research at the University of Texas was directed by
Professor Allen Bard. He was employed as a chemist from 1973 to 1977 at Rockwell International’s
Science Center in Thousand Oaks, California.

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© 2010 Taylor & Francis Group, LLC