ASTM D7600-16(2017)

Standard Test Method for Determination of Aldicarb, Carbofuran, Oxamyl and Methomyl by Liquid Chromatography/Tandem Mass Spectrometry

SIGNIFICANCE AND USE
5.1 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.4  
5.2 This test 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 test method. This test method adheres to multiple reaction monitoring (MRM) mass spectrometry.  
1.2 This test method has been developed by U.S. EPA Region 5 Chicago Regional Laboratory (CRL).  
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.  
TABLE 1 Detection Verification Level and Reporting Range    
Analyte  
DVL (ng/L)  
Reporting Range (μg/L)  
Aldicarb  
100  
1–100  
Carbofuran  
100  
1–100  
Oxamyl  
100  
1–100  
Methomyl  
100  
1–100  
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.
FIG. 1 Example Primary SRM Chromatograms Signal/Noise Ratios  
FIG. 2 Example Confirmatory SRM Chromatograms Signal/Noise Ratios  
1.4.2 The reporting limit is the concentration of the Level 1 calibration standard as shown in Table 2 for the carbamates.
TABLE 2 Concentrations of Calibration Standards (PPB)    
Analyte/Surrogate  
LV 1  
LV 2  
LV 3  
LV 4  
LV 5  
LV 6  
Aldicarb  
1  
5  
10  
25  
50  
100  
Carbofuran  
1  
5  
10  
25  
50  
100  
Oxamyl  
1  
5  
10  
25  
50  
100  
Methomyl  
1  
5  
10  
25  
50  
100  
BDMC (Surrogate)  
2  
10  
20  
50  
100  
200  
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.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 14-Jun-2017
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.06 - Methods for Analysis for Organic Substances in Water

Relations

• Replaces: ASTM D7600-16 - Standard Test Method for Determination of Aldicarb, Carbofuran, Oxamyl and Methomyl by Liquid Chromatography/Tandem Mass Spectrometry
• Effective Date: 15-Jun-2017
• Refers: ASTM D3694-96(2024) - Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
• Effective Date: 01-Apr-2024
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM E2554-18 - Standard Practice for Estimating and Monitoring the Uncertainty of Test Results of a Test Method Using Control Chart Techniques
• Effective Date: 01-Apr-2018
• Refers: ASTM E2554-18e1 - Standard Practice for Estimating and Monitoring the Uncertainty of Test Results of a Test Method Using Control Chart Techniques
• Effective Date: 01-Apr-2018
• Refers: ASTM E2554-13 - Standard Practice for Estimating and Monitoring the Uncertainty of Test Results of a Test Method Using Control Chart Techniques
• Effective Date: 01-Apr-2013
• Refers: ASTM D2777-12 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jun-2012
• Refers: ASTM D3856-11 - Standard Guide for Management Systems in Laboratories Engaged in Analysis of Water
• Effective Date: 15-Nov-2011
• Refers: ASTM D3694-96(2011) - Standard Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
• Effective Date: 01-May-2011
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM D2777-08 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Jan-2008
• Refers: ASTM E2554-07 - Standard Practice for Estimating and Monitoring the Uncertainty of Test Results of a Test Method in a Single Laboratory Using a Control Sample Program
• Effective Date: 01-May-2007
• Refers: ASTM D1129-06a - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D1129-06ae1 - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D2777-06 - Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• Effective Date: 15-Aug-2006

Overview

ASTM D7600-16(2017) is an internationally recognized standard test method developed by ASTM for the determination of specific N-methyl carbamate (NMC) pesticides-aldicarb, carbofuran, oxamyl, and methomyl-in surface and reagent water. Utilizing liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS), this method ensures qualitative and quantitative analysis of these target carbamate contaminants at trace levels. The method applies multiple reaction monitoring (MRM) mass spectrometry for precise detection, aligning with U.S. EPA regulatory interests in monitoring and managing pesticide residues in water sources.

Key Topics

• Purpose and Relevance: Addresses the measurement of pesticide residues due to their potential health risks, specifically cholinesterase inhibition, which is of regulatory concern for environmental and public health agencies.
• Analytes: Aldicarb, carbofuran, oxamyl, and methomyl-select N-methyl carbamates with a common toxicological mechanism.
• Applicability: The test method is validated for use with surface and reagent water, especially targeting potential contamination scenarios in vulnerable regions (e.g., shallow private wells in permeable soils).
• Detection and Quantitation:
  • Detection Verification Level (DVL): 100 ng/L for all analytes.
  • Reporting Range: 1–100 μg/L for each carbamate.
  • Calibration: Uses multiple calibration points (1, 5, 10, 25, 50, 100 μg/L) to ensure accuracy across the reporting range.
• Quality Control: Emphasizes method precision, bias, and robust QA/QC protocols including calibration verification, surrogate recovery, matrix spikes, and duplicates.

Applications

This standard finds practical application in:

• Drinking Water Monitoring: Ensuring regulatory compliance with EPA guidelines for pesticides in water, especially significant in regions with vulnerable groundwater sources.
• Environmental Surveillance: Used by environmental testing laboratories to screen for carbamate residues in rivers, lakes, and other surface waters.
• Public Health Protection: Supports risk assessments for food and residential exposure by providing accurate measurements of contaminant levels in water.
• Water Treatment Validation: Assists municipalities and water treatment facilities in verifying removal efficacy of carbamate pesticides.
• Research and Method Development: Serves as a reference method in scientific studies or for laboratories developing improved detection protocols for pesticides in water.

Related Standards

Professionals utilizing ASTM D7600-16(2017) may also reference or require compliance with the following related standards:

• ASTM D1129 - Terminology Relating to Water
• ASTM D1193 - Specification for Reagent Water
• ASTM D2777 - Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
• ASTM D3856 - Guide for Management Systems in Laboratories Engaged in Analysis of Water
• ASTM D3694 - Practices for Preparation of Sample Containers and for Preservation of Organic Constituents
• ASTM D5847 - Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
• ASTM E2554 - Practice for Estimating and Monitoring the Uncertainty of Test Results Using Control Chart Techniques
• EPA SW-846 - Test Methods for Evaluating Solid Waste, Physical/Chemical Methods

Practical Value

Adhering to ASTM D7600-16(2017) ensures laboratories achieve high reliability in pesticide residue determination through validated sample preparation, instrument calibration, and quality assurance practices. The standard is essential for regulatory reporting, supporting water safety, and protecting public health from the influence of carbamate pesticides, directly addressing the oversight requirements established by the U.S. EPA and international agreements on water quality.

Keywords

carbamates, aldicarb, carbofuran, oxamyl, methomyl, liquid chromatography, tandem mass spectrometry, LC/MS/MS, water analysis, pesticide residue, ASTM D7600, environmental monitoring, EPA, public health, drinking water

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D7600 −16 (Reapproved 2017)
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.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This procedure covers the determination of aldicarb,
carbofuran, oxamyl and methomyl (referred to collectively as
2. Referenced Documents
carbamates in this test method) in surface water by direct
2.1 ASTM Standards:
injection using liquid chromatography (LC) and detected with
D1129Terminology Relating to Water
tandemmassspectrometry(MS/MS).Theseanalytesarequali-
D1193Specification for Reagent Water
tativelyandquantitativelydeterminedbythistestmethod.This
D2777Practice for Determination of Precision and Bias of
test method adheres to multiple reaction monitoring (MRM)
Applicable Test Methods of Committee D19 on Water
mass spectrometry.
D3856Guide for Management Systems in Laboratories
1.2 This test method has been developed by U.S. EPA
Engaged in Analysis of Water
Region 5 Chicago Regional Laboratory (CRL).
D3694Practices for Preparation of Sample Containers and
1.3 The values stated in SI units are to be regarded as for Preservation of Organic Constituents
D5847Practice for Writing Quality Control Specifications
standard. No other units of measurement are included in this
standard. for Standard Test Methods for Water Analysis
E2554Practice for Estimating and Monitoring the Uncer-
1.4 The Detection Verification Level (DVL) and Reporting
tainty of Test Results of a Test Method Using Control
Range for the carbamates are listed in Table 1.
Chart Techniques
1.4.1 The DVL is required to be at a concentration at least
2.2 Other Documents:
3 times below the Reporting Limit (RL) and have a signal/
EPApublication SW-846Test Methods for Evaluating Solid
noise ratio greater than 3:1. Fig. 1 displays the signal/noise
Waste, Physical/Chemical Methods
ratios of the primary single reaction monitoring (SRM) transi-
tions and Fig. 2 displays the confirmatory SRM transitions at
3. Terminology
the DVLs for the carbamates.
3.1 Definitions:
1.4.2 The reporting limit is the concentration of the Level 1
3.1.1 For definitions of terms used in this standard, refer to
calibration standard as shown in Table 2 for the carbamates.
Terminology D1129.
1.5 This standard does not purport to address all of the
3.2 Definitions of Terms Specific to This Standard:
safety concerns, if any, associated with its use. It is the
3.2.1 carbamates, n—in this test method, aldicarb,
responsibility of the user of this standard to establish appro-
carbofuran, oxamyl and methomyl collectively.
priate safety and health practices and determine the applica-
3.2.2 detection verification level, DVL, n—a concentration
bility of regulatory limitations prior to use.
that has a signal/noise ratio greater than 3:1 and is at least 3
1.6 This international standard was developed in accor-
times below the reporting limit (RL).
dance with internationally recognized principles on standard-
3.2.3 independent reference material, IRM, n—amaterialof
ization established in the Decision on Principles for the
known purity and concentration obtained either from the
Development of International Standards, Guides and Recom-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This test method is under the jurisdiction ofASTM Committee D19 on Water contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
andisthedirectresponsibilityofSubcommitteeD19.06onMethodsforAnalysisfor Standards volume information, refer to the standard’s Document Summary page on
Organic Substances in Water. the ASTM website.
Current edition approved June 15, 2017. Published July 2017. Originally Available from National Technical Information Service (NTIS), U.S. Depart-
approved in 2009. Last previous edition approved in 2016 as D7600 – 16. DOI: ment of Commerce, 5285 Port Royal Road, Springfield, VA, 22161 or at http://
10.1520/D7600-16R17. 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
D7600−16 (2017)
TABLE 1 Detection Verification Level and Reporting Range
report issued for each sample lists the concentration of
Analyte DVL (ng/L) Reporting Range (µg/L) aldicarb, carbofuran, oxamyl, methomyl and the BDMC sur-
Aldicarb 100 1–100 rogate recovery.
Carbofuran 100 1–100
Oxamyl 100 1–100
5. Significance and Use
Methomyl 100 1–100
5.1 The N-methyl carbamate (NMC) pesticides: aldicarb,
carbaryl, carbofuran, formetanate hydrochloride, methiocarb,
methomyl, oxamyl, pirimicarb, propoxur, and thiodicarb have
NationalInstituteofStandardsandTechnology(NIST)orother
been identified by EPAas working through a common mecha-
reputable supplier. The IRM shall be obtained from a different
nism.Theyaffectthenervoussystembyreducingtheabilityof
lot of material than is used for calibration
the enzyme cholinesterase. Cholinesterase inhibition was the
3.3 Acronyms:
primary toxicological effect of regulatory concern to EPA in
3.3.1 CCC, n—Continuing Calibration Check
assessingtheNMC’sfood,drinkingwaterandresidentialrisks.
3.3.2 IC, n—Initial Calibration
In most of the country, NMC residues in drinking water
sources are at levels that are not likely to contribute substan-
3.3.3 LC, n—Liquid Chromatography
tially to the multi-pathway cumulative exposure. Shallow
3.3.4 LCS/LCSD, n—Laboratory Control Sample/
private wells extending through highly permeable soils into
Laboratory Control Sample Duplicate
shallow, acidic ground water represent what the EPA believes
3.3.5 MDL, n—Method Detection Limit 4
to be the most vulnerable drinking water.
3.3.6 MeOH, n—Methanol
5.2 This test method has been investigated for use with
–3
3.3.7 mM, n—millimolar,1×10 moles/L
reagentandsurfacewaterfortheselectedcarbamates:aldicarb,
3.3.8 MRM, n—Multiple Reaction Monitoring carbofuran, oxamyl, and methomyl.
3.3.9 MS/MSD, n—Matrix Spike/Matrix Spike Duplicate
6. Interferences
3.3.10 NA, adj—Not Available
6.1 Methodinterferencesmaybecausedbycontaminantsin
3.3.11 ND, n—non-detect
solvents, reagents, glassware and other apparatus producing
3.3.12 P&A, n—Precision and Accuracy
discrete artifacts or elevated baselines. All of these materials
are demonstrated to be free from interferences by analyzing
3.3.13 PPB, n—parts per billion
laboratory reagent blanks under the same conditions as
3.3.14 PPT, n—parts per trillion
samples.
3.3.15 QA, adj—Quality Assurance
6.2 All glassware is washed in hot water with a detergent,
3.3.16 QC, adj—Quality Control
rinsed in hot water followed by distilled water. The glassware
3.3.17 RL, n—Reporting Limit
is then dried and heated in an oven at 250°C for 15 to 30
minutes. All glassware is subsequently cleaned with acetone,
3.3.18 RSD, n—Relative Standard Deviation
then methanol.
3.3.19 RT, n—Retention Time
6.3 All reagents and solvents should be pesticide residue
3.3.20 SDS, n—Safety Data Sheets
purity or higher to minimize interference problems.
3.3.21 SRM, n—Single Reaction Monitoring
6.4 Matrix interferences may be caused by contaminants
3.3.22 SS, n—Surrogate Standard
that are co-extracted from the sample. The extent of matrix
3.3.23 TC, n—Target Compound
interferences can vary considerably from sample source de-
–6
3.3.24 µM, n—micromolar,1×10 moles/L pending on variations of the sample matrix.
3.3.25 VOA, n—Volatile Organic Analysis
7. Apparatus
4. Summary of Test Methods
7.1 LC/MS/MS System:
7.1.1 LiquidChromatography(LC)System—AcompleteLC
4.1 This is a performance-based method and modifications
system is needed in order to analyze samples. This should
are allowed to improve performance.
include a sample injection system, a solvent pumping system
4.2 For carbamate analysis, samples are shipped to the lab
capable of mixing solvents, a sample compartment capable of
between0°Cand6°Candanalyzedwithin7daysofcollection.
maintaining required temperature and a temperature controlled
In the lab, the samples are spiked with surrogate, filtered using
columncompartment.Asystemthatiscapableofperformingat
a syringe-driven filter unit and analyzed directly by LC/MS/
MS.
4.3 Aldicarb, carbofuran, oxamyl, methomyl, and 4-bromo-
AdditionalinformationaboutcarbamatepesticidescanbefoundontheInternet
at http://www.epa.gov.
3,5-dimethylphenyl-N-methylcarbamate (BDMC, surrogate)
AWatersAlliance High Performance Liquid Chromatography (HPLC) System
are identified by retention time and two SRM transitions. The
(a trademark of the Waters Corporation, Milford, MA), or equivalent, was found
target analytes and surrogate are quantitated using the primary
suitable for use. The multi-laboratory study included Agilent and Waters LC
SRM transitions utilizing an external calibration. The final systems.
D7600−16 (2017)
FIG. 1Example Primary SRM Chromatograms Signal/Noise Ratios
FIG. 2Example Confirmatory SRM Chromatograms Signal/Noise Ratios
D7600−16 (2017)
TABLE 2 Concentrations of Calibration Standards (PPB)
8.3 Gases—Ultrapure nitrogen and argon.
Analyte/Surrogate LV 1 LV 2 LV 3 LV 4 LV 5 LV 6
8.4 Acetonitrile (CAS # 75-05-8).
Aldicarb 1 5 10 25 50 100
8.5 Methanol (CAS # 67-56-1).
Carbofuran 1 5 10 25 50 100
Oxamyl 1 5 10 25 50 100
8.6 Acetone (CAS # 67-64-1).
Methomyl 1 5 10 25 50 100
BDMC (Surrogate) 2 10 20 50 100 200
8.7 Ammonium acetate (CAS # 631-61-8).
8.8 Ammonium hydroxide (Concentrated, CAS # 1336-21-
6).
the flows, pressures, controlled temperatures, sample volumes
8.9 Aldicarb (CAS # 116-06-3).
and requirements of the standard may be used.
8.10 Carbofuran (CAS # 1563-66-2).
7.1.2 Analytical Column —A C18 column was used to
develop this test method. Any column that achieves adequate
8.11 Oxamyl (CAS # 23135-22-0).
resolution may be used. The retention times and order of
8.12 Methomyl (CAS # 16752-77-5).
elution may change depending on the column that is used and
8.13 4-Bromo-3,5-dimethylphenyl-N-methylcarbamate
need to be monitored.
(BDMC, CAS # 672-99-1).
7.1.3 Tandem Mass Spectrometer (MS/MS) System—A
8.13.1 BDMC is used as a surrogate in this standard.
MS/MS system capable of MRM analysis. A system that is
capableofperformingattherequirementsinthisstandardmay
9. Hazards
be used.
9.1 Normal laboratory safety applies to this method. Ana-
7.2 Filtration Device:
lysts should wear safety glasses, gloves, and lab coats when
7.2.1 Hypodermic syringe—A luer-lock tip glass syringe
working in the lab. Analysts should review the Safety Data
capable of holding a syringe-driven filter unit.
Sheets (SDS) for all reagents used in this test method.
7.2.1.1 A25-mLlocktipglasssyringesizeisrecommended
since a 25-mL sample size is used in this test method.
10. Sampling
7.2.2 Filter unit —PVDF filter units were used to filter the
10.1 Sampling—Grabsamplesmustbecollectedin≥25-mL
samples.
pre-cleaned amber glass bottles withTeflon-lined caps demon-
strated to be free of interferences. This test method requires a
8. Reagents and Materials
25-mL sample size per analysis. Conventional sampling prac-
8.1 Purity of Reagents—High-performance liquid chroma-
tices should be followed. Refer to Guide D3856 and Practices
tography (HPLC) pesticide residue analysis and spectropho-
D3694.
tometry grade chemicals shall be used in all tests. Unless
10.2 Preservation—Store samples between 0°C and 6°C
indicated otherwise, it is intended that all reagents shall
from the time of collection until analysis.Analyze the sample
conform to the Committee on Analytical Reagents of the
9 within 7 days of collection.
American Chemical Society. Other reagent grades may be
used provided they are first determined to be of sufficiently
11. Preparation of LC/MS/MS
highpuritytopermittheirusewithoutaffectingtheaccuracyof
11.1 LC Chromatograph Operating Conditions:
the measurements.
11.1.1 Injection volumes of all calibration standards and
8.2 Purity of Water—Unless otherwise indicated, references
samples are 100 µL. The first sample analyzed after the
towatershallbeunderstoodtomeanreagentwaterconforming
calibrationcurveisablanktoensurethereisnocarry-over.The
toType1ofSpecificationD1193.Itmustbedemonstratedthat
gradient conditions for the liquid chromatograph are shown in
this water does not contain contaminants at concentrations
Table 3.
sufficient to interfere with the analysis.
11.1.2 Temperatures—Column, 30°C; Sample
compartment, 15°C.
AWaters (a trademark of theWaters Corporation, Milford, MA) XBridge C18,
TABLE 3 Gradient Conditions for Liquid Chromatography
150 mm × 2.1 mm, 3.5 µm particle size, or equivalent, has been found suitable for
use.
Percent Percent 50 mmolar
Time Flow Percent
A Waters Quattro micro API mass spectrometer (a trademark of the Waters
95 % Water ⁄ NH OAc/NH OH in
4 4
(min) (µL/min) CH CN
Corporation, Milford, MA), or equivalent, was found suitable for use. The
5% CH CN 95 % Water/5 % CH CN
3 3
multi-laboratory study included Applied Biosystems and Waters mass spectrom-
0 300 0 95 5
eters.
2 300 0 95 5
A Millex HV Syringe Driven Filter Unit PVDF 0.45 µm (Millipore
4 300 30 65 5
Corporation, Catalog # SLHV033NS; a trademark of the Waters Corporation,
6 300 35 60 5
Milford, MA) has been found suitable for use for this test method, any filter unit
8 300 35 60 5
may be used that meets the performance of this test method may be used.
10 300 75 20 5
Reagent Chemicals, American Chemical Society Specifications, American
11.5 300 75 20 5
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
12 300 95 0 5
listed by the American Chemical Society, see Annual Standards for Laboratory
18 300 95 0 5
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
20 300 0 95 5
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, 23 300 0 95 5
MD.
D7600−16 (2017)
11.1.3 Seal Wash—Solvent: 50% Acetonitrile/50% Water; 12. Calibration and Standardization
Time: 5 minutes.
12.1 The mass spectrometer must be calibrated per manu-
11.1.4 Needle Wash—Solvent: 50% Acetonitrile/50% Wa-
facturer specifications before analysis. In order that analytical
ter; Normal wash, approximately 13 second wash time.
values obtained using this test method are valid and accurate
11.1.5 Autosampler Purge—Three loop volumes.
within the confidence limits of the test method, the following
11.1.6 Specific instrument manufacturer wash/purge speci-
proceduresmustbefollowedwhenperformingthetestmethod.
fications should be followed in order to eliminate sample
12.2 Calibration and Standardization—To calibrate the
carry-over in the analysis of carbamates.
instrument,analyzesixcalibrationstandardscontainingthesix
11.2 Mass Spectrometer Parameters:
concentration levels of the carbamates and BDMC surrogate
11.2.1 In order to acquire the maximum number of data
prior to analysis as shown in Table 2. A calibration stock
points per SRM channel while maintaining adequate
standard solution is prepared from standard materials or
sensitivity, the tune parameters may be optimized according to
purchased as certified solutions. Stock standard solution A
your instrument. Each peak requires at least 10 scans per peak
(Level 6) containing aldicarb, carbofuran, oxamyl, methomyl
for adequate quantitation. This standard contains only one
andBDMCispreparedatLevel6concentrationandaliquotsof
surrogate and four target compounds. The MRM experiment
that solution are diluted to prepare Levels 1 through 5. The
windows were set to acquire methomyl and oxamyl in one
following steps will produce standards with the concentration
experimentwindowwhilealdicarb,carbofuranandBDMCare
values shown in Table 2. The analyst is responsible for
intheirindividualMRMexperimentwindows.Thisisrequired
recording initial component weights carefully when working
becausethechromatographicresolutionseparatingoxamyland
with pure materials and correctly carrying the weights through
methomyl was not achieved. Variable parameters regarding
the dilution calculations.
retention times, SRM Transitions and cone and collision
12.2.1 Prepare stock standard solution A (Level 6) by
energies are shown in Table 4.
adding to a 100-mL volumetric flask individual methanol
The instrument is set in the Electrospray (+) positive setting.
solutions of the following: 50 µL of aldicarb, carbofuran,
Capillary Voltage: 3.5 kV
oxamyl and methomyl each at 0.2 g/Land 50 µLof BDMC at
Cone: Variable depending on analyte (Table 4)
Extractor: 2 Volts 0.4g/L,diluteto100mLwith90%water/10%methanol.The
RF Lens: 0.2 Volts
preparation of the Level 6 standard can be accomplished using
Source Temperature: 120°C
different volumes and concentrations of stock solutions as is
Desolvation Temperature: 300°C
accustomed in the individual laboratory. Depending on stock
Desolvation Gas Flow: 500 L/hr
Cone Gas Flow: 25 L/hr
concentrations prepared, the solubility at that concentration
Low Mass Resolution 1: 14.5
will have to be ensured.
High Mass Resolution 1: 14.5
Ion Energy 1: 0.5 12.2.2 Aliquots of Solution A are then diluted with 90%
Entrance Energy: –1
water/10% methanol to prepare the desired calibration levels
Collision Energy: Variable depending on analyte (Table 4)
in 2-mL amber glass LC vials. The calibration vials must be
Exit Energy: 2
Low Mass Resolution 2: 15 used within 24 hours to ensure optimum results. Stock calibra-
High Mass resolution 2: 15
tion standards are routinely replaced every 7 days if not
Ion Energy 2: 0.5
previously discarded for quality control failure. Calibration
Multiplier: 650
–3
Gas Cell Pirani Gauge: 3.3 × 10 Torr standards are not filtered.
Inter-Channel Delay: 0.02 seconds
12.2.3 Inject each standard and obtain a chromatogram for
Inter-Scan Delay: 0.1 seconds
each one.An external calibration technique is used monitoring
Repeats: 1
Span: 0 Daltons the primary and confirmatory SRM transition of each analyte.
Dwell: 0.1 Seconds
Calibration software is utilized to conduct the quantitation of
TABLE 4 Retention Times, SRM Ions, and Analyte-Specific Mass Spectrometer Parameters
Retention Cone Voltage SRM Mass Transition Collision Energy
Analyte Primary/ Confirmatory Collision Energy (eV)
time (min) (Volts) (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
D7600−16 (2017)
the target analytes and surrogate using the primary SRM criteria, the problem must be corrected and either: all samples
transition. The ratios of the primary/confirmatory SRM transi- in the batch must be re-analyzed against a new calibration
tion area counts are given in Table 4. These are given as curve, or the affected results must be qualified with an
informative and will vary depending on the individual tuning indication that they do not fall within the performance criteria
conditions. The primary/confirmatory SRM transition area of the test method. If the analyst inspects the vial containing
ratio must be within 30% of the individual labs accepted the end calibration check standard and notices that the sample
primary/confirmatory SRM transition area ratio. The primary evaporated affecting the concentration, a new end calibration
SRM transition of each analyte is used for quantitation and the check standard may be made and analyzed. If this new end
confirmatory SRM transition for confirmation. This gives calibration check standard has a percent deviation less than
added confirmation by isolating the parent ion, fragmenting it 30% from the calculated concentration for the target analytes
intotwoproductions,andrelatingittotheretentiontimeinthe and surrogate the results may be reported unqualified.
calibration standard.
12.3 All samples are prepared using ClassAglass volumet-
12.2.4 The calibration software manual should be consulted
ric glassware. The sample volume used throughout this test
to use the software correctly.The quantitation method is set as
method is 25 mL. Every sample, the entire 25 mL volume, is
an external calibration using the peak areas in ppt or ppb units
filtered through the filtration device described in Section 7.2
as long as the analyst is consistent. Concentrations may be
only after all required spiking solutions are added and mixed
calculated using
...