EPA-R2-72-079
October 1972
Environmental Protection Technology Series
Liquid Chromatography of
Carbamate Pesticides
National Environmental Research Center
Office of Research and Monitoring
U.S. Environmental Protection Agency
Corvallis, Oregon 97330
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Agency, have
been grouped into five series. These five broad
categories were'established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are;
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
H. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards..
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EPA-R2-72-079
October 1972
LIQUID CHROMATOGRAPHY OF CARBAMATE PESTICIDES
by
Alfred D. Thruston, Jr.
Southeast Environmental Research Laboratory
College Station Road
Athens, Georgia 30601
Project 16020 EWC
Program Element 1B1027
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND MONITORING
U.S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, B.C., 20402 - Price 55 cents
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ABSTRACT
A commercial liquid chromatograph was evaluated and
found useful for analysis of carbamate pesticides.
Liquid chromatography retention times for 23 carbamate
pesticides are given. The UV detector required 20 to
1500 ng for the pesticides studied to give a 25% full-
scale recorder response.
111
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CONTENTS
Section Page
I Conclusions 1
II Introduction 3
III Experimental 5
IV Results and Discussion 9
V References 15
v
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FIGURES
PAGE
1 CHROMATOGRAM OF CARBAMATE PESTICIDES
ON PERMAPHASE ODS COLUMN 11
2 CHROMATOGRAM OF CARBAMATE PESTICIDES
ON PERMAPHASE ETH COLUMN 12
3 CHROMATOGRAM OF SWEP, EXTRACTED FROM
WATER SPIKED AT 2 yg/£ LEVEL 14
VI
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TABLES
No. Page
1 Chemical Names and Sources of the
Carbamate Pesticides 6
2 Retention Times and Sensitivities of
Various Carbamates on Permaphase ODS
Column 10
3 Retention Times and Sensitivities of
Various Carbamates on Permaphase ETH
Column 13
VI1
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SECTION I
CONCLUSIONS
Liquid chromatography shows promise for analysis of
carbamate pesticide residues. The technique provides
separations with speed and resolution comparable to
those of gas chromatography. Ambient or near ambient
temperature can be used with heat-labile compounds.
Sensitivity is 2 to 3 orders of magnitude less than
that of electron capture gas chromatography but is
still adequate for many compounds.
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SECTION II
INTRODUCTION
Most carbamate pesticides cannot be analyzed directly
by gas chromatography unless conversion to more
suitable derivatives is carried out (1/2), because they
are thermally unstable. Techniques, such as semi-
quantitative thin-layer chromatography (3,4) or quan-
titative ultra-violet spectrometry (5), vary in
selectivity and sensitivity.
Liquid chromatography (LC) is a relatively new analytical
tool that offers selectivity and moderate sensitivity for
analysis of these heat-labile compounds. LC separation
and detection of Sevin (carbaryl) and its hydrolysis
product, 1-naphthol, from plant extracts have been
reported (6), but no comprehensive list of retention
times and sensitivities of various carbamate pesticides
has been published.
A liquid chromatograph is similar to a gas chromatograph;
each has an injection port, a packed column, and a
detector. A liquid mobile phase under pressure is used
in LC instead of a carrier gas as in gas chromatography.
Many compounds that are not volatile enough or too heat-
labile for analysis by gas chromatography will partition
between the LC stationary and mobile phases.
Two DuPont stationary phase columns were evaluated for
analysis of carbamate pesticides—Permaphase ODS (for
non-polar compounds) and Permaphase ETH (for more polar
type carbamates).
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SECTION III
EXPERIMENTAL
Liquid ahromatograph.--A DuPont Model 820 liquid
chromatograph equipped with an ultraviolet photometric
detector that measures the absorbance at 254 nm was
used. The following columns and conditions were
employed:
(1) 1m x 2mm id stainless steel column, packed
with Permaphase ODS (octadecyl silane). Mobile
phases were 6% and 30% methanol in water. A
pressure of 1000 psi at 50° C maintained a flow
of 1 ml/min.
(2) 1m x 2mm id stainless steel column, packed
with Permaphase ETH (ether). Mobile phases
were hexane, 1% isopropanol/hexane, and 4%
isopropanol/hexane. A pressure of 400 psi at
40° C maintained a flow of 1 ml/min.
Solvents.--Spectrograde hexane, isopropanol, methanol
and methylene chloride.
Standard carbamate solutions.--Standards (Table I)
were prepared as isopropanol solutions.
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Table 1. Chemical names and sources of the carbamate pesticides
Common or Trade Name
Chemical Name
Source
BaygonR (aprocarb)
FuradanR (carbofuran)
MatacilR (aminocarb)
MobamR
SevinR (carbaryl)
Landrin
UC 10854
UC 8454
Carbanolate
RE 5305
Mesurol
Zectran1
R
2-isopropoxyphenyl-N-methyl
carbamate
7-(2 ,3-dihydro-2,2-dimethyl)-
benzofuranyl-N-methyl carbamate
4-dimethylamino-3-methylphenyl-
N-me'thyl carbamate
4-benzothienyl-N-methyl carbamate
1-naphthyl-N-methyl carbamate
3,4,5-trimethylphenylmethyl-
carbamate
3-isopropylphenyl-N-methyl
carbamate
1- (5,6,7,8-tetrahydro)-naphthyl-
N-methyl carbamate
3,4-xylyl-6-chloro-N-methyl
carbamate
3-sec-butylphenyl-N-methyl
carbamate
4-methylthio-3,5-dimethylphenyl-
N-methyl carbamate
4-dimethylamino-3,5-dimethy1-
phenyl-N-methyl carbamate
Chemagro Corp.
Niagara Chem. Div.,
FMC Corp.
Chemagro Corp.
Mobil Chem. Co.
Union Carbide Corp.
Shell Development Corp.
Union Carbide Corp.
Union Carbide Corp.
Upjohn Co.
Chevron Chem. Co.
Chemagro Corp.
Dow Chem. Co.
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Table 1. Chemical names and sources of the carbamate pesticides
Common or Trade Name
Chemical Name
Source
SirmateR, 2,3-isomer
Sirmate/ 3,4-isomer
BuxR
AzakR (terbutol)
Benomyl (Dupont
Fungicide 1991)
IPC
CIPC
DimetilanR
TemikR
Swep
Barban
2/3-Dichlorobenzyl-N-methylcarbamate
3,4-Dichlorobenzy1-N-methylcarbamate
3-(l-Methylbutyl) phenyl
methylcarbamate
2,6-Di-tert.-butyl-4-methylphenyl-
N-methylcarbamate
Methyl l-(butylcarbamoyl)-2-
benzimidazole carbamate
isopropyl-N-phenyl carbamate
isopropyl-N-(3-chlorophenyl)
carbamate
3-(l-N,N-dimethylcarbamoyl-5-
methyl)-pyrazolyl-N,N-dimethyl
carbamate
2-methyl-2-methylthio propion-
aldehyde-0-methylcarbamoyl oxime
methyl-N-(3,4-dichlorophenyl)
carbamate
4-chloro-2-butynyl-N-(3-chloro-
phenyl) carbamate
FDAa
FDAa
Chevron Chem. Corp.
Hercules Powder Co.
E. I. DuPont de
Nemours and Co.
PPG
PPG
Geigy Chem. Corp.
Union Carbide Corp.
Niagara Chem. Div.,
FMC Corp.
Gulf Res. & Dev. Co.
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Table 1. Chemical names and sources of the carbamate pesticides
Common or Trade Name Chemical Name Source
Thiram bis(dimethylthiocarbamoyl) E.I. Dupont de Nemours
disulfide and Co.
MyloneR(dazomet) 3,5-dimethyl-l,3,5- Union Carbide Corp.
tetrahydrothiadiazine-2-thione
LannateR(methorny1) methyl N-[ (methy lcarbamoyl)oxy]- E.I. Dupont de Nemours
thioacetimidate and Co.
aFood and Drug Administration, Washington, D.C,
00
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SECTION IV
RESULTS AND DISCUSSION
Table 2 lists retention times and sensitivities for
17 carbamates on Permaphase ODS. The first 12 eluted
as sharp symmetrical peaks within 10 minutes with 6%
methanol in water as the mobile phase; Figure 1 shows
a chromatogram of five of these carbamate pesticides
and 1-naphthol. The last five in Table 2 had excessive
retention times, which were shortened by changing the
mobile phase to 30% methanol in water.
Figure 2 shows chromatograms of seven of the more polar
carbamates on the Permaphase ETH column. A change in
mobile phase polarity from 1% isopropanol in hexane to
4% isopropanol in hexane causes significant changes in
retention times. Table 3 summarizes retention times and
minimum sensitivities of nine polar carbamates.
For these carbamates, the sensitivity of the UV detector
ranges from 20-1500 ng, a level suitable for pesticide
residue analysis. This work was done with pure solutions
to obtain standard retention times. Natural sample
extracts were not studied systematically.
The LC technique was applied to a study of the kinetics
of Sevin degradation by micro-organisms. Aqueous samples
of 4-8 yl were injected into the LC without prior clean-
up or extraction. Sevin was observed in these samples in
the 11-33 mg/A range based on comparison with standard
solutions.
Considerably lower detection limits can be obtained by
concentrating the sample. For example, a liter of tap
water, spiked with 2 yg/1 of swep (methyl dichlorophenyl
carbamate) was extracted with methylene chloride (3) and
concentrated to 200 yl. Figure 3 shows a distinct swep
peak in the chromatogram of a 5-yl injection of the
concentrate. '
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Table 2. Retention times and sensitivities of various
carbamates on Permaphase ODS column, 50° C, methanol/
water mobile phase, 1000 psi,lml/min flow rate, UV
detector.
Chemical
Name
Baygon
Furadan
Matacil
Mob am
Sevin
Landrin
UC 10854
UC 8454
Carbanolate
l-naphthola
RE-5305
Mesurol
Zectran
Sinuate, 2,3-
isomer
Sirmate, 3,4-
isomer
Bux
Benomyl
Azak
6% MeOH/
H20 Rj.Cmin)
1.50
1.60
2.00
2.10
2.60
3.25
3.40
3.50
3.60
4.30
7.20
7.65
8.30
30% MeOH/
H20 Rt(min)
2.30
2.60
3.50
6.10
6.35
Min . Amount
to give 25%
FSD (ng)
250
300
50
25
100
1000
1000
1000
1000
250
1000
200
200
1500
1500
1500
1500
1500
ahydrolysis product of Sevin
Abroad skewed peak
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4
Minutes
8
Figure 1.
Chromatogram of carbamate pesticides on Perma-
phase ODS column. 6% methanol/94% water mobile
phase. 1, Furadan; 2, Matacil; 3, Sevin;
4, Landrin; 5, 1-naphthol (hydrolysis product
of Sevin); 6, Mesurol.
11
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H
to
(a)
(b)
4
Minutes
8
Figure 2
Chromatogram of carbamate pesticides on Permaphase ETH column:
(a) 1% isopropanol/99% hexane mobile phase. 1, CIPC; 2, Dimetilan;
3, Temik; 4, barban. (b) 4% isopropanol/96% hexane mobile phase.
1, swep; 2, barban; 3, Mylone; 4, Lannate.
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Table 3. Retention times and sensitivities of various
carbamates on Permaphase ETH column, 40 °C, 0 to 4%
isopropanol/hexane mobile phase, 400 psi,lml/min
flow rate, UV detector.
Chemical
Name
I PC
CIPC
Dimetilan
Temik
Swep
Barb an
Thiram
Mylone
Lannate
Hexane
Rt (min)
1.52
1.92
1% IPA/Hex
R-t (min)
1.50
1.50
2.10
2.66
3.00
7.20
4% IPA/Hex
R£ (min)
1.68
1.80
2.96
2.90
3.82
4.88
Min. Amount
to give 25%
FSD (ng)
250
500
1000
100
20
400
50
100
500
13
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V
0
J
0 4
Minutes
Figure 3. Chromatogram of swep, extracted from water
spiked at 2 yg/5. level. 1, solvent peak;
2, swep.
14
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SECTION V
REFERENCES
1. Holden, E.R., Jones, W.M. , and Beroza, M. ,
"Determination of Residues of Methyl- and
Dimethyl Insecticides by Gas Chromatography of
Their 2,4-Dinitroaniline Derivatives," J. Agr.
Food Chem., 17, No. 1, pp 56-59 (1969).
2. Butler, L.I. and McDonough, L.M., "Specific GLC
Method for Determining Residues of Carbaryl by
Electron Capture Detection after Derivative
Formation," JAOAC 53, No. 3, pp 495-498 (1970).
3. Abbott, D.C., Blake, K.W., Tarrant, K.R., and
Thomson, J. , "Thin-Layer Chromatographic Separa-
tion, Identification, and Estimation of Residues
of Some Carbamate and Allied Pesticides in Soil
and Water," J. Chromatog. 30, pp 136-142 (1967).
4. El-Dib, M.A., "Thin-Layer Chromatographic Detection
of Carbamate and Phenylurea Pesticide Residues in
Natural Waters," JAOAC 53, No. 4, pp 756-760 (1970).
5. Aly, O.M., "Spectrophotometric Determination of
Sevin in Natural Waters," JAWWA 59, No. 7, pp 906-
912 (1967) .
6. "The Analysis of Carbaryl and Its Major Hydrolysis
Product 1-Naphthol in Plant Extracts," Chromato-
graphic Methods 820 M7, February 13, 1970 (a
DuPont Instruments" Information Sheet).
15
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1
5
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2
Subject Fu'ld & Group
05A
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
orgamzat.on u>s> Environmental Protection Agency
Southeast Environmental Research Laboratory
Athens, Georgia
Title
LIQUID CHROMATOGRAPHY OF CARBAMATE PESTICIDES
10
Authors)
Thruston, A.D., Jr.
16
Project Designation
PROJECT # 16020 EWC
21
Note
22
Citation
Environmental Protection Agency report
number EPA-R2-72-OT9, October 1972.
23
Descriptors (Starred First)
*Analytical techniques, *Chromatography, *Pesticides, *Carbamate
pesticides.
25
Identifiers (Starred First)
*Liquid chromatography, retention times.
27
Abstract
A commercial liquid chromatograph was evaluated and found useful
for analysis of carbamate pesticides. Liquid chromatography retention
for 23 carbamate pesticides are given. The UV detector required 20 to
1500 ng for the pesticides studied to give a 25% full-scale recorder
response. (Thruston—Southeast Environmental Research Laboratory)
Abstractor
Tbr-nat-rm
-TV.
Institution
Southeast Environmental Research Laboratory
WR;102 (REV. JULY 1969)
WRS1 C
SEND TO: WATER RESOURCES SC I EN Tl FIC INFORMATION CENTER
U.S DEPARTMENT OF THE INTERIOR
WASHINGTON. O. C. 20240
-. U. S. GOVERNMENT PRINTING OFFICE : 1972-514-149/74
« Sl>0: I9S9-SS9-339
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