Analysis of Pesticides in Food and Environmental Samples - Chapter 1 doc

Analysis of
Pesticides in
Food and
Environmental
Samples
ß 2007 by Taylor & Francis Group, LLC.
ß 2007 by Taylor & Francis Group, LLC.
CRC Press is an imprint of the
Taylor & Francis Group, an informa business
Boca Raton London New York
Edited by José L. Tadeo
Analysis of
Pesticides in
Food and
Environmental
Samples
ß 2007 by Taylor & Francis Group, LLC.
CRC Press
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Analysis of pesticides in food and environmental samples / editor, Jose L. Tadeo.
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Includes bibliographical references and index.
ISBN 978-0-8493-7552-1 (alk. paper)
1. Pesticide residues in food. 2. Food Analysis. 3. Pesticides I. Tadeo, Jose L.
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Contents
Preface
Editor
Contrib utors
Chapt er 1 Pesticides : Classi fication and Properties

José L. Tadeo, Consuel o Sánchez -Brunet e,
and Lorena González
Chapt er 2 Sample Hand ling of Pe sticides in Food and Env ironment al
Samples
Esther Turiel and Antoni o Mart ín-Esteban
Chapt er 3 Analysis of Pesticides by Chroma togra phic Tec hnique s
Coupled wi th Mass Spectromet ry
Simon Hird
Chapt er 4 Immunoas says and Biosens ors
Jeanet te M. Van Emon, Jane C. Chuang, Kili an Di ll,
and Guoh ua Xio ng
Chapt er 5 Quality Assurance
Árpád Ambru s
Chapt er 6 Determinat ion of Pesticides in Food of Vegetal Origin
Frank J. Schenck and Jon W. Wong
Chapt er 7 Determinat ion of Pesticides in Food of Animal Origin
Antoni a Garrido Frenich , Jose Luis Mart inez,
and Adrian Covaci
Chapt er 8 Determinat ion of Pesticides in Soil
Con suelo Sánchez -Brunet e, Beatriz Albero,
and José L. Tadeo
Chapter 9 Determination of Pesticides in Water
Jay Gan and Svetlana Bonda renko
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Chapter 10 Sampling and Analysis of Pesticides in the Atmosphere
Maurice Millet
Chapter 11 Levels of Pesticides in Food and Food Safety Aspects
Kit Gra nby, Ann ette Peters en, Susan S. Her rmann,
and Mett e Erecius Pou lsen
Chapter 12 Monitoring of Pesticides in the Environment

Ioannis Konstan tinou, Dimi tra Hela, Dimitra Lambrop oulou,
and Tr iantafyllos Albani s
ß 2007 by Taylor & Francis Group, LLC.
Preface
You should go on learning for as long as your ignorance lasts;
and, if the proverb is to be believed, for the whole of your life.
Lucius Annaeus Seneca
Consumer concerns on food safety and society awareness of chemical contaminants
in the environment have increased in the past few years. As a consequence , more
restrictions in the use of chemical products have been imposed at national and
international levels.
Pesticides are widely used for the control of weeds, diseases, and pests of
cultivated plants all over the world, mainly since after Second World War, with
the discovery of some organic compounds with good insectici de or herbicide
activity. At present, around 2.5 million tons of pesticides are used annually and the
number of registered active substances is higher than 500.
However, as pesticides are toxic substances that may have undesirable effects,
their use has to be regulated. Risk assessment of pesticides requires information on
the toxicological and ecotoxicological properties of these compounds as well as on
their levels in food and environmental compartments. Therefore, reliable analytical
methods are needed to carry out the monitoring of pesticide residues in those
matrices.
Analysis of Pesticides in Food and Environmental Samples focuses on the
analytical methodologies developed for the determination of these compounds and
on their levels in food and in the environment. It includes infor mation on the different
pesticides used, sample preparation methods, quality assurance, chromatographic
techniques, immunoassays, pesticide determination in food, soil, water, and air, and
the results of their monitoring in food and environmental compartments. I think that
this timely and up-to-date work can significantly improve the information in this
research area and contribute to a better understanding of the behavior of pesticides

that will lead to an improvement of their use.
My sincere thanks to everyone who has contributed and particularly to all the
contributors of the different chapters of Analysis of Pesticides in Food and Environ-
mental Samples.
This work is dedicated to Teresa, my wife.
José L. Tadeo
ß 2007 by Taylor & Francis Group, LLC.
ß 2007 by Taylor & Francis Group, LLC.
Editor
José L. Tadeo, PhD in chemistry, is a senior researcher at the National Institute for
Agricultural and Food Research and Technology, Instituto Nacional de Investigación
y Tecnología Agraria y Alimentaria in Madrid, Spain. He graduated with a degree in
chemistry in June 1972 from the University of Valencia and began his research
career at the Institute of Agrochemistry and Food Technology, Spanish Council for
Scientific Research, in Valencia, investigating natural components of plants with
insecticide activity. In 1976, he was engaged in research of analytical methodologies
for the determination of pesticide residues in food, water, and soil at the Jealott’s Hill
Research Station in the United Kingdom.
In 1977, Dr. Tadeo was a research scientist at the Institute for Agricultural
Research in Valencia where his work focused on the study of the chemical compo-
sition of citrus fruits and the behavior of fungicides used during postharvest of fruits.
In 1988, he became a senior researcher at the Instituto Nacional de Investigación
y Tecnología Agraria y Alimentaria. During his stay at the Plant Protection Depart-
ment, the main research lines were the analysis of herbicide residues and the study of
their persistence and mobility in soil.
His current research at the Environment Department of the Instituto Nacional de
Investigación y Tecnología Agraria y Alimentaria is the analysis of pesticides
and other contaminants in food and environmental matrices and the evaluation of
exposure to biocides and existing chemicals. He has published numerous scientific
papers, monographs, and book chapters on these topics. He has been a member of

national and international working groups for the evaluation of chemicals, and he is
currently involved in the assessment of biocides at the international level.
ß 2007 by Taylor & Francis Group, LLC.
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Contributors
Triantafyllos Albanis
Department of Chemistry
University of Ioannina
Ioannina, Greece
Beatriz Albero
Department of Environment
Instituto Nacional de Investigación y
Tecnología Agraria y Alimentaria
Madrid, Spain
Árpád Ambrus
Hungarian Food Safety Office
Budapest, Hungary
Svetlana Bondarenko
Department of Environmental Sciences
University of California
Riverside, California
Jane C. Chuang
Battelle
Columbus, Ohio
Adrian Covaci
Toxicological Centre
University of Antwerp
Wilrijk, Belgium
Kilian Dill
Antara Biosciences

Mountain View, California
Jay Gan
Department of Environmental Sciences
University of California
Riverside, California
Antonia Garrido Frenich
Department of Analytical Chemistry
University of Almeria
Almeria, Spain
Lorena González
Department of Environment
Instituto Nacional de Investigación y
Tecnología Agraria y Alimentar ia
Madrid, Spain
Kit Granby
The National Food Institute
Technical University of Denmark
Søborg, Denmark
Dimitra Hela
Department of Business Administration
of Agricultural Pr oducts and Food
University of Ioannina
Agrinio, Greece
Susan S. Herrmann
The National Food Institute
Technical University of Denmark
Søborg, Denmark
Simon Hird
Central Science Laboratory
Sand Hutton, York, United Kingdom

Ioannis Konstantinou
Department of Environmental and
Natural Resources Management
University of Ioannina
Agrinio, Greece
ß 2007 by Taylor & Francis Group, LLC.
Dimitra Lambropoulou
Department of Chemistry
University of Ioannina
Ioannina, Greece
Antonio Martín-Esteban
Department of Environment
Instituto Nacional de Investigación y
Tecnología Agraria y Alimentar ia
Madrid, Spain
Jose Luis Martinez
Department of Analytical Chemistry
University of Almeria
Almeria, Spain
Maurice Millet
Laboratoire de Physico-Chimie de
l’Atmosphère
Centre de Géochimie de la Surface
Université Louis Pasteur
Strasbourg, France
Annette Petersen
The National Food Institute
Technical University of Denmark
Søborg, Denmark
Mette Erecius Poulsen

The National Food Institute
Technical University of Denmark
Søborg, Denmark
Consuelo Sánchez-Brunete
Department of Environment
Instituto Nacional de Investigación y
Tecnología Agraria y Alimentar ia
Madrid, Spain
Frank J. Schenck
Southeast Regional Laboratory
U.S. Food and Drug Administration
Office of Regulatory Affairs
Atlanta, Georgia
José L. Tadeo
Department of Environment
Instituto Nacional de Investigación y
Tecnología Agraria y Alimentaria
Madrid, Spain
Esther Turiel
Department of Environment
Instituto Nacional de Investigación y
Tecnología Agraria y Alimentaria
Madrid, Spain
Jeanette M. Van Emon
National Exposure Research Laboratory
U.S. Environmental Protection Agency
Las Vegas, Nevada
Jon W. Wong
Center for Food Safety and Applied
Nutrition

U.S. Food and Drug Administration
College Park, Maryland
Guohua Xiong
National Exposure Research Laboratory
U.S. Environmental Protection Agency
Las Vegas, Nevada
ß 2007 by Taylor & Francis Group, LLC.
1
Pesticides: Classification
and Properties
José L. Tadeo, Consuelo Sánchez-Brunete,
and Lorena González
CONTENTS
1.1 Introduction 2
1.2 Herbicides 4
1.2.1 Amides 5
1.2.2 Benzoic Acids 5
1.2.3 Carbamates 6
1.2.4 Nitriles 7
1.2.5 Nitroanilines 8
1.2.6 Organophosphorus 10
1.2.7 Phenoxy Acids 10
1.2.8 Pyridines and Quaternary Ammonium Compounds 12
1.2.9 Pyridazines and Pyridazinones 13
1.2.10 Triazines 14
1.2.11 Ureas 15
1.2.11.1 Phenylureas 15
1.2.11.2 Sulfonylureas 16
1.3 Insecticides 16
1.3.1 Benzoylureas 16

1.3.2 Carbamates 16
1.3.3 Organochlorines 19
1.3.4 Organophosphorus 20
1.3.5 Pyrethroids 20
1.4 Fungicides 23
1.4.1 Azoles 23
1.4.2 Benzimidazoles 23
1.4.3 Dithiocarbamates 26
1.4.4 Morpholines 26
1.4.5 Miscellaneous 27
1.5 Mode of Action 28
1.5.1 Herbicides 28
1.5.1.1 Amino Acid Synthesis Inhibitors 28
1.5.1.2 Cell Division Inhibitors 30
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1.5.1.3 Photosynthesis Inhibitors 30
1.5.2 Insecticides 30
1.5.2.1 Signal Interference in the Nervous System 30
1.5.2.2 Inhibitors of Cholinesterase 31
1.5.2.3 Inhibitors of Chitin Synthesis 31
1.5.3 Fungicides 31
1.5.3.1 Sulfhydryl Reagents 31
1.5.3.2 Cell Division Inhibitors 31
1.5.3.3 Inhibitors of Ergosterol Synthesis 32
1.6 Toxicity and Risk Assessment 32
References 34
1.1 INTRODUCTION
A pesticide is any substance or mixture of substances, natural or synthetic, formu-
lated to control or repel any pest that competes with humans for food, destroys
property, and spreads disease. The term pest includes insects, weeds, mammals, and

microbes, among others [1].
Pesticides are usually chemical substances, although they can be sometimes
biological agents such as virus or bacteria. The active portion of a pesticide,
known as the active ingredient, is generally formulated by the manufacturer as
emulsifiable concentrates or in solid particles (dust, granules, soluble powder, or
wettable powder). Many commercial formulations have to be diluted with water
before use and contain adjuvants to improve pesticide retention and absorption by
leaves or shoots.
There are different classes of pesticides according to their type of use. The main
pesticide groups are herbicides, used to kill weeds and other plants growing in places
where they are unwanted; insecticides, employed to kill insects and other arthropods;
and fungicides, used to kill fungi. Other types of pesticides are acaricides, mollusci-
cides, nematicides, pheromones, plant growth regulators, repellents, and rodenticides.
Chemical substances have been used by human to contr ol pests from the
beginning of agriculture. Initially, inorganic compounds such as sulfur, arsenic,
mercury, and lead were used. The discovery of dichlorodiphenyltrichloroethane
(DDT) as an insecticide by Paul Müller in 1939 caused a great impact in the control
of pests and soon became widely used in the world. At that time, pesticides had a
good reputation mainly due to the control of diseases like malaria transmitted by
mosquitoes and the bubonic plague transmitted by fleas, both killing millions of
people over time. Nevertheless, this opinion changed after knowing the toxic effects
of DDT on birds, particularly after the publication of the book Silent Spring by
Rachel Carson in 1962 [2]. At present, due to the possible toxic effects of pesticides
on human health and on the environment, there are strict regulations for their
registration and use all over the world, especially in developed countries. However,
although some progress is achieved in the biological control and in the development
of resistance of plants to pests, pesticides are still indispensable for feeding and
protecting the world population from diseases. It has been estimated that around
one-third of the crop production would be lost if pesticides were not applied.
ß 2007 by Taylor & Francis Group, LLC.

Pesticide use h as incre ased 50-fol d since 1950 and around 2.5 million tons of
industri al pesti cides per year are used nowa days. Figure 1.1 show s the time course o f
pesticide sales during the last years.
Acco rding to the Euro pean Crop Protec tion Associa tion (ECPA) Annu al Rep ort
2001 –2002, the main agric ultural areas of pesticide usage are North Ameri ca,
Europe, and Asia with 31.9%, 23.8%, and 22.6%, respectively, in 2001 (Figure 1.2).
These percentages of pesticide sales are expressed in millions of euros and, although
the mentioned regions are the most important agricultural areas in the global pesticide
market, their relative position may vary due to changes in the currency exchange rates,
climatic condit ions, and national policies on agric ultural support and regulatio ns.
The amoun t of pe sticides appli ed in a deter mined geograp hical area depen ds on
the climatic condition s an d on the outbreak of pests and d iseases of a particula r year.
Neverthel ess, herbicides are the main group of pesticide s used worldwide, foll owed
by insecticides and fungicides (Figure 1.3).
Millions of U.S. dollars
20,000
22,000
24,000
26,000
28,000
30,000
32,000
1990 1992 1994 1996 1998 2000 2002 2004 2006
FIGURE 1.1 World market of pesticides since 1990. Values are expressed in millions of
U.S. dollars. (From European Crop Protection Association (ECPA) Review 2005–2006,
http:==www.ecpa.be.)
0
2,000
4,000
6,000

8,000
10,000
North
America
Europe Asia Latin
America
Other
Millions of euros
FIGURE 1.2 Regional pesticide sales expressed in millions of euros. (From ECPA Annual
Report 2001–2002, http:==www.ecpa.be.)
ß 2007 by Taylor & Francis Group, LLC.
The de velopment of a new chemic al as a pesti cide takes at presen t nearl y
15 years and around $20 million, and only one co mpound out of 10,000 compo unds
init ially tested might reach, on average, final comm ercia l production. The regis tra-
tion of a pesticide for its applicati on on a particula r crop requi res a complete set of
data to prove its ef ficacy a nd safe use. This normally incl udes d ata on physicochem -
ical proper ties , analyt ical methods, e ffi cacy, toxi cology , ecotox icology , and fate and
beh avior in the envir onmen t. Residue s left on crops after pesticide appli cation have
bee n restrict ed in develo ped countr ies to g uaranty a safe food consum ption. The
maxi mum resi due level s (MR Ls) in different foods have been estab lished according to
go od agric ultural pract ices, the observed toxi c effects of the pesticide , and the amoun t
of food consum ed. MR Ls are no rmally fi xed in relation with the admi ssible da ily
inta ke (ADI) of pestic ides, which is the amoun t of pesticide that can be ingested daily
du ring the whole life without showing an appreci able advers e effect . MR Ls are
propos ed by the Joint FAO=WHO Meeting on Pesti cide Residue s (JMPR) and
recom mende d for adoption by the Codex Comm ittee on Pesti cide Res idues [3,4].
In the following sections of this chapte r, the mai n class es of pesticide s (herbi-
cides , insec ticides, an d fungi cides) wi ll be described together wi th their mai n
ph ysicochemi cal proper ties and principal uses. These data have been gather ed
mai nly from The Pesti cide Manual [5] as well as from the primary manufactur e

source s [6,7] and other available p ublications [8,9].
1.2 HERBICIDES
The implem entation of mecha nization in agricultu re has increased the ability of
hu man to contr ol weed s and cultivat e crops; herbicides have p layed a main part in
this development ; and a higher propor tion of farmers would be needed if herbicides
were not used.
Herbicides can be classified as soil- or foliage-applied compounds, which are
normally absorbed by roots or leaf tissues, respectively. These compounds can be
0
10
20
30
40
50
60
70
World USA Europe
Herbicides Insecticides Fungicides
%
FIGURE 1.3 Distribution of the market (%) per pesticide type. (From Environmental Protec-
tion Agency (USEPA), pesticides industry sales and usage, 2001, http:==www.epa.gov=
oppbead1=pestsales= and ECPA Annual Report 2001–2002, http:==www.ecpa.be.)
ß 2007 by Taylor & Francis Group, LLC.
total or selective herbi cides. Total herbi cides can kill all vegetation , wher eas selec t-
ive herbi cides can control weeds without affect ing the crop. These chemical sub-
stances may be applied at different crop stages, such as presowi ng and pre- or
postemerg ence, and these diff erent treatmen ts will be used dependi ng on the weed
needed to be con trolled in a particula r crop. The selec tivity of a herbi cide may
depend on a d ifferential plant uptake , translocat ion, or met abolism , as wel l as on
differences at the sit e of action. A know ledge of p hysicochem ical proper ties, that is,

vapor press ure (V. p.), octano l=water pa rtition coef ficient (K
ow
, expres sed in the
logarithm ic form log P), and solubili ty in water allo ws the fate and behavi or of
such c hemicals in the envir onmen t to be predi cted.
In addition, herbi cides can be classi fied accordi ng to their chemical c omposit ion.
The princ ipal ph ysicochemi cal p roperties , together with the field persisten ce and
major uses of repres entative herbicides , grouped in their main chemi cal class es, are
described late r.
1.2.1 A MIDES
A large varie ty of compounds form this group of herbic ides, which have the
follow ing general formula: R
1
– CO–N –(R
2
,R
3
).
The key compo nents of this group are the N-s ubstituted chlor oacetamid es and
the subst ituted anilides.
Propanil Alachlor
Cl
Cl
NHCOCH
2
CH
3
CH
2
CH

3
N
CH
2
CH
3
COCH
2
Cl
CH
2
OCH
3
The chlor oaceta mides are effective preemergenc e herbi cides for annual grasses and
annual broad- leaved weeds but they also have foliar contac t activity. In general,
these compounds are soil applied and used in various horticultural crops, such as
maize, soybean, and sugarcane. These herbicides are norm ally absorbed by shoots
and roots and they are, in general , nonpers istent compo unds in soil (Table 1.1).
1.2.2 BENZOIC ACIDS
This group is mainly formed by chlorinated derivatives of substituted benzoic acids.
Cl
CO
2
H
OCH
3
Cl
Dicamba
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The benzoi c acid herbi cides are kno wn to have grow th regulatin g and auxin acti vity

proper ties . These compo unds are especi ally used to contr ol deep-r ooted perennial
weed s and ap plied as salt s or esters (Table 1.2).
1.2.3 C ARBAMATES
Car bamates are ester s of the carbamic acid (R
1
–O –CO –NR
2
R
3
) and toget her with
thio carbam ates (R
1
–S–CO –NR
2
R
3
) represen t a broad group of herbic ides, freque ntly
app lied to soil in preemergenc e.
NHCO
2
CH(CH
3
)
2
[CH
3
(CH
2
)
2

]
2
NC(O)SCH
2
CH
3
Propham EPTC
TABLE 1.1
Chem ical Nam es an d Properties of Amide Herbicides
Common
Name IUPAC Name
Vapor
Pressure
mPa (258 C)
K
ow
log P
Water
Solubility
mg=L
(258 C)
Half-Life
in Soil
(Days)
Acetochlor
C
14
H
20
ClNO

2
2-Chloro-N-ethoxymethyl-
6
0
-ethylacet- o-toluidide
0.005 4.14 223 8–18
Alachlor
C
14
H
20
ClNO
2
2-Chloro-2
0
,6
0
-diethyl- N-
methoxymethylacetanilide
2.0 3.09 170
a
1–30
Butachlor
C
17
H
26
ClNO
2
N-Butoxymethyl-2-chloro-2

0
,6
0
-
diethylacetanilide
0.24 — 23
a
12
Metolachlor
C
15
H
22
ClNO
2
2-Chloro-6-ethyl- N-
(2-methoxy-1-methylethyl)
acet- o-toluidide
4.2 2.9 488 20
Propachlor
C
11
H
14
ClNO
2-Chloro-N-isopropyl acetanilide 10 1.4–2.3 580 4
Propanil
C
9
H

9
Cl
2
NO
3
0
,4
0
-Dichloro propionanilide 0.05 3.3 130
a
2–3
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council, 2000;
http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www.epa
.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in Pesticide
Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
a
208C.
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These compo unds are root o r shoot absorbed and are freque ntly used to contr ol
annual grass es and broad- leaved weed s in peas, beet, and other horticultural c rops.
These herbi cides are normally decompo sed by soil mic roorganism s in 3 –5 weeks.
Their mai n physicochem ical proper ties are summari zed in Table 1.3.
1.2.4 NITRILES
Bromox ynil and ioxynil are the hydroxy benzoni triles used as herbicides .
Bromoxynil Ioxynil
CN
Br
OH
Br

CN
I
OH
I
They are form ulated as salts or octano ate ester s and foliage app lied to control broad-
leaved weed s in cereals and horticultural crops. The se compo unds are used in
postemerg ence and freque ntly applied in combinati on with other herbicides to
extend the spect rum of weed speci es to be contr olled. They have a low persi stence
in soil (Tab le 1.4).
TABLE 1.2
Chemica l Nam es and Properti es of Benz oic Acid Herbicides
Common
Name
IUPAC
Name
Vapor
Pressure
mPa (258 C)
K
ow
log P
Water
Solubility
g=L (258C)
Half-Life
in Soil
(Days)
Chloramben
C
7

H
5
Cl
2
NO
2
3-Amino-2,5-
dichlorobenzoic acid
——0.7 14–21
Chlorthal-dimethyl
C
10
H
6
Cl
4
O
4
Dimethyl
tetrachloroterephthalate
0.21 4.28 0.5 3 10
À3
33
Dicamba
C
8
H
6
Cl
2

O
3
3,6-Dichloro-o-
methoxybenzoic acid
1.67 À1.88 6.1 <14
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council, 2000;
http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www.epa
.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in Pesticide
Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
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1.2.5 NITROANILINES
The se c ompounds are derivativ es of 2,6-di nitroaniline .
Pendimethalin
NHCH(CH
2
CH
3
)
2
NO
2
NO
2
H
3
C
H
3
C

Ni troanilines are a group of herbicides with sim ilar physicochem ical proper ties, such
as low water solubility and high octanol–water partition coefficient. These compounds
are soil-applied herbicides used to control annual grasses and many broad-leaved
TABLE 1.3
Chem ical Nam es an d Properties of Carbamat e Herbi cides
Common
Name
IUPAC
Name
Vapor
Pressure
mPa
(258C)
K
ow
log P
Water
Solubility
mg=L (258 C)
Half-Life
in Soil
(Days)
Chlorpropham
C
10
H
12
ClNO
2
Isopropyl-3-

chlorocarbanilate
1.3 3.76 89 30–65
Desmedipham
C
16
H
16
N
2
O
4
Ethyl-3-phenylcarbamoyloxy
phenylcarbamate
4 3 10
À5
3.39 7
a
34
EPTC
C
9
H
19
NOS
S-Ethyl
dipropylthiocarbamate
0.01 3.2 375 6–30
Molinate
C
9

H
17
NOS
S-Ethyl azepane-1-
carbothioate
746 2.88 970 8–25
Phenmedipham
C
16
H
16
N
2
O
4
Methyl-3-
(3-methylcarbaniloyloxy)
carbanilate
1.3 3 10
À6
3.59 4.7 25
Propham
C
10
H
13
NO
2
Isopropyl
phenylcarbamate

Sublimes
slowly
— 250
a
5–15
Thiobencarb
C
12
H
16
ClNOS
S-4-Chlorobenzyl
diethylthiocarbamate
2.93 3.42 30
a
14–21
Triallate
C
10
H
16
Cl
3
NOS
S-2,3,3-Trichloroallyl
diisopropyl(thiocarbamate)
16 4.6 4 56–77
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council, 2000;
http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www.epa
.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in Pesticide

Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
a
208C.
ß 2007 by Taylor & Francis Group, LLC.
weeds in a wi de varie ty of crops. The 2,6-dinit roaniline s posses s a mark ed general
herbicide activity . Sub stitution at the third and=or fourth position of the ring or on the
amino group modi fies the degree of herbi cidal activity . In general, they have a
certain persisten ce in soil and are normally soil incor porated due to thei r signi fi cant
vapor pressure (Table 1.5).
TABLE 1.4
Chemica l Nam es and Properti es of Nit rile Herbicides
Common
Name
IUPAC
Name
Vapor
Pressure
mPa (208C)
K
ow
log P
Water
Solubility
mg=L (208 C)
Half-Life
in Soil
(Days)
Bromoxynil
C

7
H
3
Br
2
NO
3,5-Dibromo-4-
hydroxybenzonitrile
6.3 3 10
À 3
2.8 130 10
Ioxynil
C
7
H
3
I
2
NO
4-Hydroxy-3,5-
diiodobenzonitrile
<1 3.43 50 10
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council, 2000;
http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www.epa
.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in Pesticide
Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
TABLE 1.5
Chemica l Nam es and Properti es of Nit roaniline Herbicides
Common

Name
IUPAC
Name
Vapor
Pressure
mPa
(258 C)
K
ow
log P
Water
Solubility
mg=L
(258 C)
Half-Life
in Soil
(Days)
Butralin
C
14
H
21
N
3
O
4
N-sec-Butyl-4-tert-butyl-2,
6-dinitroaniline
0.77 4.93 1 14
Ethalfluralin

C
13
H
14
F
3
N
3
O
4
N-Ethyl-a,a,a-tri fluoro-N-
(2-methylallyl)-2,6-dinitro-
p-toluidine
11.7 5.11 0.3 25 –46
Pendimethalin
C
13
H
19
N
3
O
4
N-(1-Ethylpropyl)-2,6-
dinitro-3,4-xylidine
4 5.18 0.3
a
90 –120
Trifluralin
C

13
H
16
F
3
N
3
O
4
a,a,a-Tri fluoro-2,6-dinitro-
N ,N-dipropyl-p-toluidine
6.1 4.83
a
0.22 57 –126
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council, 2000;
http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www.epa
.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in Pesticide
Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
a
208C.
ß 2007 by Taylor & Francis Group, LLC.
1.2.6 ORGANOPHOSPHORUS
HO
2
CCH
2
NHCH
2
P(OH)

2
O
GlufosinateGlyphosate
CH
3
PCH
2
CH
2
CHCO
2
H
O
OH NH
2
Gl yphosate and glufo sinate are broad spect rum, nonsel ective, poste mergen ce co ntact
herbi cides ac tive only for foliar applicati on. The y are extens ively used in vario us
app lications for weed con trol in aquati c systems and vegeta tion contr ol in noncrop
areas. Aminome thylphosph onic acid (AM PA) is the maj or degrada tion product of
glypho sate found in plant s, wat er, and soil . The main proper ties of these compo unds
are show n in Table 1.6.
1.2.7 P HENOXY A CIDS
Ph enoxy acids are a comm on name given to a group of compo unds formed by a
phenoxy radical linked to a low carbon number alkanoic acid, such as 2,4-dichlorophe-
no xyacetic acid (2,4-D, ace tic acid) or mecoprop (propi onic acid). Some herbicides
of this group are form ed by ster eoiso mers, which are comm ercialize d as singl e
ena nthiomer s or racemic mixtures .
TABLE 1.6
Chem ical Nam es an d Properties of Organoph osphorus Herbicides
Common

Name
IUPAC
Name
Vapor
Pressure
mPa (258 C)
K
ow
log P
Water
Solubility
g=L (258 C)
Half-Life
in Soil
(Days)
Glyphosate
C
3
H
8
NO
5
P
N -(Phosphonomethyl)
glycine
1.3 3 10
À2
<À3.2 11.6 3–174
Glufosinate-ammonium
C

5
H
15
N
2
O
4
P
Ammonium
4-[hydroxy(methyl)
phosphinoyl]-
DL-
homoalaninate
<0.1
a
<0.1 1370 7–20
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council,
2000; http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www
.epa.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in
Pesticide Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
a
208C.
ß 2007 by Taylor & Francis Group, LLC.
2,4-D Diclofop
Cl
Cl
OCH
2
CO

2
H
Cl O
Cl
O CHCO
2
H
CH
3
These horm one type herbi cides were discovered during the Se cond Worl d War and,
some years later, the phenoxy –phenoxy acids like diclofop were introdu ced to
overcom e the probl em of selective control of grass weed s in cereal crops. These
compo unds are active by contac t and by translocation from leaves to roots of
perenni al weed s and they are also used in preem ergence applicati ons to the soil for
the contr ol of young seedl ings. The chlor ophenoxy compo unds are selec tive agains t
broad- leaved annual weed s in cereal and grass crops. In general , they have a short
persisten ce in soil (Table 1.7).
TABLE 1.7
Chemica l Nam es and Properti es of Phe noxy Acid Herbi cides
Common
Name
IUPAC
Name
Vapor
Pressure
mPa (258 C)
K
ow
log P
Water

Solubility
mg=L (208 C)
Half-Life
in Soil
(Days)
2,4-D
C
8
H
6
Cl
2
O
3
2,4-Dichlorophenoxy
acetic acid
1.86 3 10
À2
0.04 23,180 <7
Diclofop
C
15
H
12
Cl
2
O
4
(RS)-2-[4-(2,4-Dichlorophenoxy)
phenoxy]propionic acid

9.7 3 10
À6
2.81 122,700 30
Fenoxaprop-P
C
16
H
12
ClNO
5
(R)-2-[4-(6-Chloro-1,3-benzoxazol
-2-yloxy)phenoxy]propionic acid
1.8 3 10
À1a
1.83 61,000 1–10
Fluazifop-P
C
15
H
12
F
3
NO
4
(R)-2-[4-(5-Trifluoromethyl-2-
pyridyloxy)phenoxy]propionic acid
7.9 3 10
À4a
À0.8 780 <32
MCPA

C
9
H
9
ClO
3
4-Chloro-(2-methylphenoxy)acetic
acid
2.3 3 10
À2a
À0.71 274
b
<7
Mecoprop-P
C
10
H
11
ClO
3
(R)-2-(4-Chloro- o-tolyloxy)
propionic acid
0.4
a
0.02 860 3–13
Quizalofop-
P-ethyl
C
19
H

17
ClN
2
O
4
Ethyl(R)-2-[4-
(6-chloroquinoxalin-2-yloxy)
phenoxy]propionate
1.1 3 10
À4a
4.66 0.61 1
Triclopyr
C
7
H
4
Cl
3
NO
3
3,5,6-Trichloro-2-pyridyloxyacetic
acid
0.2 À0.45 8.10 46
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council, 2000;
http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www.epa
.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in Pesticide
Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
a
208C.

b
258C.
ß 2007 by Taylor & Francis Group, LLC.
1.2.8 P YRIDINES AND QUATERNARY A MMONIUM C OMPOUNDS
The herbi cide group of pyrid ines, also named bipyridyl ium, is formed by paraqua t
and diquat. The se compo unds were develo ped as the result of observ ation s that
qu aternary amm onium germicid es, such as cetyl tri methylam monium brom ide,
desic cated young plants. Other quaternary amm onium compo unds, like chlormequa t
and mepiqua t, have been develo ped and used as plant grow th regulators to incre ase
yiel ds in cereal s, promote flower ing in ornam ental plants, and imp rove frui t sett ing in
ho rticultural p lants and trees .
N
ϩ
CH
3
ϩ
NH
3
C
ϩ
N
N
ϩ
Paraquat Diquat
Pa raquat and diquat are broad spect rum herbi cides absorbed by leaves , but they are
no t translocat ed in suf ficient quantiti es to kill the roots of perenni al weed s. These
compo unds are very stro ng bases because of their quater nary ammon ium structure s
and are rapid ly adsorb ed and inactivat ed in soil . Therefor e, these compounds are not
effect ive as preemergenc e herbicides . They h ave a high water solub ility a nd low
octano l –water partiti on coef ficient (T able 1.8 ), and are avail able commerci ally as

TABLE 1.8
Chem ical Nam es an d Properties of Pyridi ne Herbicides and Quater nary
Am monium Com pounds
Common
Name
IUPAC
Name
Vapor
Pressure
mPa (208C)
K
ow
log P
Water
Solubility
g=L (208 C)
Half-Life
in Soil
(Days)
Diquat dibromide
C
12
H
12
Br
2
N
2
1,1
0

-Ethylene-2,2
0
-
bipyridyldiylium
dibromide
<0.013 À4.6 700 <7
Paraquat dichloride
C
12
H
14
Cl
2
N
2
1,1
0
-Dimethyl-4,4
0
-
bipyridinium dichloride
<0.01
a
À4.5 620 <7
Chlormequat chloride
C
5
H
13
Cl

2
N
2-Chloroethyl
trimethyl ammonium
<0.01 À1.59 1000 1–28
Mepiquat chloride
C
7
H
16
ClN
1,1
0
-Dimethyl-piperidinium
chloride
<0.01 À2.82 500 10–97
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council, 2000;
http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www.epa
.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in Pesticide
Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
a
258C.
ß 2007 by Taylor & Francis Group, LLC.
dibromi de or dichl oride salts. These herbi cides are strongly adsorb ed in soil, requi r-
ing acid digestio n for severa l hours for thei r desorp tion .
1.2.9 PYRIDAZINES AND P YRIDAZINONES
Pyrida te and pyrid azinon es, like nor fl urazon and chlor idazon , are incl uded in this
group.
N

N
H
3
CHN
Cl
CF
3
N
NCl
CH
3
(CH
2
)
7
SCO
O
Norflurazon Pyridate
O
They are contac t-selective herbi cides with foliar activity and are used in pre- or
postemerg ence to contr ol annual grasses, broad- leaved weed s, and grass y weed s on
cereals, mai ze, rice, and some other crops. In general, the pyrida zinone herbi cides are
long last ing in soil (T able 1.9).
TABLE 1.9
Chemica l Nam es and Properti es of Py ridazine and Pyridaz inon e Herbi cides
Common
Name
IUPAC
Name
Vapor

Pressure
mPa (258C)
K
ow
log P
(258 C)
Water
Solubility
mg=L (208C)
Half-Life
in Soil
(Days)
Chloridazon
C
10
H
8
ClN
3
O
5-Amino-4-chloro-2-
phenylpyridazin-3(2H)-one
< 0.01
a
1.19 340 21 –76
Norflurazon
C
12
H
9

ClF
3
N
3
O
4-Chloro-5-methylamino-
2-(a,a ,a-trifl uoro-m-tolyl)
pyridazin-3(2H)-one
3.8 3 10
À 3
2.45 34
b
45 –180
Pyridate
C
19
H
23
ClN
2
O
2
S
6-Chloro-3-phenylpyridazin-
4-yl-S-octylthiocarbonate
4.8 3 10
À 4a
4.01 ca. 1.5 < 3
Sources: Data from Tomlin, C. (Ed.) in The Pesticide Manual, British Crop Protection Council, 2000;
http:==ec.europa.eu=food=plant=protection=evaluation=exist_subs_rep_en.htm; http:==www.epa

.gov=opprd001=factsheets=; Hornsby, A.G., Wauchope, R.D., and Herner, A.E. in Pesticide
Properties in the Environment, Springer-Verlag, New York, 1996; De Liñan, C. in
Farmacología Vegetal, Ediciones Agrotecnicas S.L., 1997.
a
208C.
b
258C.
ß 2007 by Taylor & Francis Group, LLC.