ASTM D7600-09
(Test Method)Standard Test Method for Determination of Aldicarb, Carbofuran, Oxamyl and Methomyl by Liquid Chromatography/Tandem Mass Spectrometry
Standard Test Method for Determination of Aldicarb, Carbofuran, Oxamyl and Methomyl by Liquid Chromatography/Tandem Mass Spectrometry
SIGNIFICANCE AND USE
The N-methyl carbamate (NMC) pesticides: aldicarb, carbaryl, carbofuran, formetanate hydrochloride, methiocarb, methomyl, oxamyl, pirimicarb, propoxur, and thiodicarb have been identified by EPA as working through a common mechanism. They affect the nervous system by reducing the ability of the enzyme cholinesterase. Cholinesterase inhibition was the primary toxicological effect of regulatory concern to EPA in assessing the NMC’s food, drinking water and residential risks. In most of the country, NMC residues in drinking water sources are at levels that are not likely to contribute substantially to the multi-pathway cumulative exposure. Shallow private wells extending through highly permeable soils into shallow, acidic ground water represent what the EPA believes to be the most vulnerable drinking water.
This method has been investigated for use with reagent and surface water for the selected carbamates: aldicarb, carbofuran, oxamyl and methomyl.
SCOPE
1.1 This procedure covers the determination of aldicarb, carbofuran, oxamyl and methomyl (referred to collectively as carbamates in this test method) in surface water by direct injection using liquid chromatography (LC) and detected with tandem mass spectrometry (MS/MS). These analytes are qualitatively and quantitatively determined by this method. This method adheres to multiple reaction monitoring (MRM) mass spectrometry.
1.2 This test method has been developed in support of the National Homeland Security Research Center, US EPA by Region 5 Chicago Regional Laboratory.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 The Detection Verification Level (DVL) and Reporting Range for the carbamates are listed in Table 1.
1.4.1 The DVL is required to be at a concentration at least 3 times below the Reporting Limit (RL) and have a signal/noise ratio greater than 3:1. Fig. 1 displays the signal/noise ratios of the primary single reaction monitoring (SRM) transitions and Fig. 2 displays the confirmatory SRM transitions at the DVLs for the carbamates.
1.4.2 The reporting limit is the concentration of the Level 1 calibration standard as shown in Table 2 for the carbamates.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7600 – 09
Standard Test Method for
Determination of Aldicarb, Carbofuran, Oxamyl and
Methomyl by Liquid Chromatography/Tandem Mass
Spectrometry
This standard is issued under the fixed designation D7600; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This procedure covers the determination of aldicarb, 2.1 ASTM Standards:
carbofuran, oxamyl and methomyl (referred to collectively as D1129 Terminology Relating to Water
carbamates in this test method) in surface water by direct D1193 Specification for Reagent Water
injection using liquid chromatography (LC) and detected with D2777 Practice for Determination of Precision and Bias of
tandem mass spectrometry (MS/MS).These analytes are quali- Applicable Test Methods of Committee D19 on Water
tatively and quantitatively determined by this method. This D3856 Guide for Good Laboratory Practices in Laborato-
method adheres to multiple reaction monitoring (MRM) mass ries Engaged in Sampling and Analysis of Water
spectrometry. D3694 Practices for Preparation of Sample Containers and
1.2 This test method has been developed in support of the for Preservation of Organic Constituents
National Homeland Security Research Center, US EPA by D5847 Practice for Writing Quality Control Specifications
Region 5 Chicago Regional Laboratory. for Standard Test Methods for Water Analysis
1.3 The values stated in SI units are to be regarded as E2554 Practice for Estimating and Monitoring the Uncer-
standard. No other units of measurement are included in this tainty of Test Results of a Test Method in a Single
standard. Laboratory Using a Control Sample Program
1.4 The Detection Verification Level (DVL) and Reporting 2.2 Other Documents:
Range for the carbamates are listed in Table 1. EPApublication SW-846 Test Methods for Evaluating Solid
1.4.1 The DVL is required to be at a concentration at least Waste, Physical/Chemical Methods
3 times below the Reporting Limit (RL) and have a signal/
3. Terminology
noise ratio greater than 3:1. Fig. 1 displays the signal/noise
ratios of the primary single reaction monitoring (SRM) transi- 3.1 Definitions:
3.1.1 detection verification level (DVL), n—a concentration
tions and Fig. 2 displays the confirmatory SRM transitions at
the DVLs for the carbamates. that has a signal/noise ratio greater than 3:1 and is at least 3
times below the reporting limit (RL).
1.4.2 The reporting limit is the concentration of the Level 1
calibration standard as shown in Table 2 for the carbamates. 3.1.2 reporting limit (RL), n—the concentration of the
lowest-level calibration standard used for quantification.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.1.3 carbamates, n—in this test method, aldicarb, carbo-
furan, oxamyl and methomyl collectively.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 3.2 Abbreviations:
3.2.1 ppt—parts per trillion, ng/L
bility of regulatory limitations prior to use.
3.2.2 ND—non-detect
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This test method is under the jurisdiction of ASTM Committee D19 on Water Standards volume information, refer to the standard’s Document Summary page on
andisthedirectresponsibilityofSubcommitteeD19.06onMethodsforAnalysisfor the ASTM website.
Organic Substances in Water. Available from National Technical Information Service (NTIS), U.S. Depart-
Current edition approved Dec. 1, 2009. Published January 2010. DOI: 10.1520/ ment of Commerce, 5285 Port Royal Road, Springfield, VA, 22161 or at http://
D7600-09. www.epa.gov/epawaste/hazard/testmethods/index.htm.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7600 – 09
TABLE 1 Detection Verification Level and Reporting Range
6.3 All reagents and solvents should be pesticide residue
Analyte DVL (µg/L) Reporting Range (µg/L) purity or higher to minimize interference problems.
6.4 Matrix interferences may be caused by contaminants
Aldicarb 100 1–100
Carbofuran 100 1–100
that are co-extracted from the sample. The extent of matrix
Oxamyl 100 1–100
interferences can vary considerably from sample source de-
Methomyl 100 1–100
pending on variations of the sample matrix.
7. Apparatus
4. Summary of Test Methods
7.1 LC/MS/MS System
4.1 This is a performance-based method and modifications
7.1.1 Liquid Chromatography (LC) System—A complete
are allowed to improve performance.
LC system is needed in order to analyze samples. A system
4.2 For carbamate analysis, samples are shipped to the lab
that is capable of performing at the flows, pressures, controlled
between0°Cand6°Candanalyzedwithin7daysofcollection.
temperatures, sample volumes and requirements of the stan-
In the lab, the samples are spiked with surrogate, filtered using
dard may be used.
a syringe driven Millex HV PVDF filter unit and analyzed
7.1.2 Analytical Column-Waters—XBridgeC18,150mm 3
directly by LC/MS/MS.
2.1 mm, 3.5 µm particle size, or equivalent.
4.3 Aldicarb, carbofuran, oxamyl, methomyl and 4-bromo-
7.1.3 Tandem Mass Spectrometer (MS/MS) System—A
3,5-dimethylphenyl-N-methylcarbamate (BDMC, surrogate)
MS/MS system capable of MRM analysis. A system that is
are identified by retention time and two SRM transitions. The
capable of performing at the requirements in this standard may
target analytes and surrogate are quantitated using the primary
be used.
SRM transitions utilizing an external calibration. The final
7.2 Filtration Device
report issued for each sample lists the concentration of aldi-
7.2.1 Hypodermic syringe—Alocktipglasssyringecapable
carb, carbofuran, oxamyl, methomyl and the BDMC surrogate
of holding a Millex HV Syringe Driven Filter Unit PVDF 0.45
recovery.
µm (Millipore Corporation, Catalog # SLHV033NS) or similar
may be used.
5. Significance and Use
7.2.1.1 A25-mLlock tip glass syringe size is recommended
5.1 The N-methyl carbamate (NMC) pesticides: aldicarb,
since a 25-mL sample size is used in this test method.
carbaryl, carbofuran, formetanate hydrochloride, methiocarb,
7.2.2 Filter—Millex HV Syringe Driven Filter Unit PVDF
methomyl, oxamyl, pirimicarb, propoxur, and thiodicarb have
0.45 µm (Millipore Corporation, Catalog # SLHV033NS) or
been identified by EPAas working through a common mecha-
similar may be used.
nism.They affect the nervous system by reducing the ability of
the enzyme cholinesterase. Cholinesterase inhibition was the
8. Reagents and Materials
primary toxicological effect of regulatory concern to EPA in
8.1 Purity of Reagents—High-performance liquid chroma-
assessingtheNMC’sfood,drinkingwaterandresidentialrisks.
tography (HPLC) pesticide residue analysis and spectropho-
In most of the country, NMC residues in drinking water
tometry grade chemicals shall be used in all tests. Unless
sources are at levels that are not likely to contribute substan-
indicated otherwise, it is intended that all reagents shall
tially to the multi-pathway cumulative exposure. Shallow
conform to the Committee on Analytical Reagents of the
private wells extending through highly permeable soils into
American Chemical Society. Other reagent grades may be
shallow, acidic ground water represent what the EPA believes
4 used provided they are first determined to be of sufficiently
to be the most vulnerable drinking water.
highpuritytopermittheirusewithoutaffectingtheaccuracyof
5.2 This method has been investigated for use with reagent
the measurements.
and surface water for the selected carbamates: aldicarb, carbo-
8.2 Purity of Water—Unless otherwise indicated, references
furan, oxamyl and methomyl.
towatershallbeunderstoodtomeanreagentwaterconforming
toType 1 of Specification D1193. It must be demonstrated that
6. Interferences
this water does not contain contaminants at concentrations
6.1 Method interferences may be caused by contaminants in
sufficient to interfere with the analysis.
solvents, reagents, glassware and other apparatus producing
8.3 Gases—Ultrapure nitrogen and argon.
discrete artifacts or elevated baselines. All of these materials
are demonstrated to be free from interferences by analyzing
laboratory reagent blanks under the same conditions as
AWatersAlliance High Performance Liquid Chromatography (HPLC) System
samples.
was used to develop this test method. The multi-laboratory study included Agilent,
6.2 All glassware is washed in hot water with a detergent,
Thermo Electron and Waters LC systems.
rinsed in hot water followed by distilled water. The glassware
A Waters Quattro micro API mass spectrometer was used to develop this test
method. The multi-laboratory study includedAgilent,Applied Biosystems, Thermo
is then dried and heated in an oven at 250°C for 15 to 30
Electron, Varian and Waters mass spectrometers.
minutes. All glassware is subsequently cleaned with acetone,
Reagent Chemicals, American Chemical Society Specifications, American
then methanol.
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
listed by the American Chemical Society, see Annual Standards for Laboratory
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Additional information about carbamate pesticides can be found on the Internet and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
at http://www.epa.gov (2009). MD.
D7600 – 09
FIG. 1 Example Primary SRM Chromatograms Signal/Noise Ratios
FIG. 2 Example Confirmatory SRM Chromatograms Signal/Noise Ratios
D7600 – 09
TABLE 2 Concentrations of Calibration Standards (PPB) TABLE 3 Gradient Conditions for Liquid Chromatography
Analyte/Surrogate LV 1 LV 2 LV 3 LV 4 LV 5 LV 6 Percent
Percent 95 % 50 mmolar
Aldicarb 1 5 10 25 50 100 Time Flow Percent
Water/ 5 % NH OAc/NH OH
4 4
Carbofuran 1 5 10 25 50 100 (min) (µL/min) CH CN
CH CN in 95 % Water/5 %
Oxamyl 1 5 10 25 50 100
CH CN
Methomyl 1 5 10 25 50 100
BDMC (Surrogate) 2 10 20 50 100 200 0 300 0 95 5
2 300 0 95 5
4 300 30 65 5
6 300 35 60 5
8 300 35 60 5
8.4 Acetonitrile (CAS # 75-05-8). 10 300 75 20 5
11.5 300 75 20 5
8.5 Methanol (CAS # 67-56-1).
12 300 95 0 5
8.6 Acetone (CAS # 67-64-1).
18 300 95 0 5
8.7 Ammonium acetate (CAS # 631-61-8). 20 300 0 95 5
23 300 0 95 5
8.8 Ammonium hydroxide (Concentrated, CAS # 1336-21-
6).
8.9 Aldicarb (CAS # 116-06-3).
11.1.1 Injection volumes of all calibration standards and
8.10 Carbofuran (CAS # 1563-66-2).
samples are 100 µL. The first sample analyzed after the
8.11 Oxamyl (CAS # 23135-22-0).
calibrationcurveisablanktoensurethereisnocarry-over.The
8.12 Methomyl (CAS # 16752-77-5).
gradient conditions for the liquid chromatograph are shown in
8.13 4-Bromo-3,5-dimethylphenyl-N-methylcarbamate
Table 3.
(BDMC, CAS # 672-99-1).
11.1.2 Temperatures—Column, 30°C; Sample compart-
8.13.1 BDMC is used as a surrogate in this standard.
ment, 15°C.
11.1.3 Seal Wash—Solvent: 50 % Acetonitrile/50 % Water;
9. Hazards
Time: 5 minutes.
9.1 Normal laboratory safety applies to this method. Ana-
11.1.4 Needle Wash—Solvent: 50 % Acetonitrile/50 % Wa-
lysts should wear safety glasses, gloves, and lab coats when
ter; Normal wash, approximately 13 second wash time.
working in the lab.Analysts should review the Material Safety
11.1.5 Autosampler Purge—Three loop volumes.
Data Sheets (MSDS) for all reagents used in this method.
11.1.6 Specific instrument manufacturer wash/purge speci-
fications should be followed in order to eliminate sample
10. Sampling
carry-over in the analysis of carbamates.
10.1 Sampling—Grab samples must be collected in
11.2 Mass Spectrometer Parameters :
$25-mL pre-cleaned amber glass bottles with Teflon-lined
11.2.1 In order to acquire the maximum number of data
caps demonstrated to be free of interferences. This test method
points per SRM channel while maintaining adequate sensitiv-
requires a 25-mL sample size per analysis. Conventional
ity, the tune parameters may be optimized according to your
sampling practices should be followed. Refer to Guide D3856
instrument. Each peak requires at least 10 scans per peak for
and Practices D3694.
adequate quantitation. This standard contains only one surro-
10.2 Preservation—Store samples between 0°C and 6°C
gate and four target compounds. The MRM experiment win-
from the time of collection until analysis. Analyze the sample
dows were set to acquire methomyl and oxamyl in one
within 7 days of collection.
experiment window while aldicarb, carbofuran and BDMC are
in their individual MRM experiment windows.This is required
11. Preparation of LC/MS/MS
because the chromatographic resolution separating oxamyl and
11.1 LC Chromatograph Operating Conditions : methomyl was not achieved. Variable parameters regarding
TABLE 4 Retention Times, SRM Ions, and Analyte-Specific Mass Spectrometer Parameters
Analyte Primary/ Confirmatory Retention time (min) Cone Voltage (Volts) Collision Energy (eV) SRM Mass Transition Collision Energy
(Parent > Product) (eV)
Primary 10 7 208.2 > 115.9
Aldicarb 11.00 2.12
Confirmatory 10 15 208.2 > 88.7
Primary 27 12 222.2 > 165.2
Carbofuran 12.85 1.20
Confirmatory 27 20 222.2 > 123
Primary 15 8 237.2 > 71.6
Oxamyl 8.25 2.38
Confirmatory 15 8 237.2 > 89.8
Primary 17 8 163.1 > 87.7
Methomyl 8.45 1.58
Confirmatory 17 8 163.1 > 105.8
Primary 25 24 258.1 > 122
BDMC (Surrogate) 14.50 1.31
Confirmatory 25 9 258.1 > 201.2
D7600 – 09
retention times, SRM Transitions and cone and collision 12.2.3 Inject each standard and obtain a chromatogram for
energies are shown in Table 4. each one.An external calibration technique is used monitoring
the primary and confirmatory SRM transition of each analyte.
The instrument is set in the Electrospray (+) positive setting.
Capillary Voltage: 3.5 kV
Calibration software is utilized to conduct the quantitation of
Cone: Variable depending on analyte (Table 4)
the target analytes and surrogate using the primary SRM
Extractor: 2 Volts
transition. The ratios of the primary/confirmatory SRM transi-
RF Lens: 0.2 Volts
Source Temperature: 120°C
tion area counts are given in Table 4. These are given as
Desolvation Temperature: 300°C
informative and will vary depending on the individual tuning
Desolvation Gas Flow: 500 L/h
...
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