1、Designation: D7600 092Standard Test Method forDetermination of Aldicarb, Carbofuran, Oxamyl andMethomyl by Liquid Chromatography/Tandem MassSpectrometry1This standard is issued under the fixed designation D7600; the number immediately following the designation indicates the year oforiginal adoption
2、or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEThis test method was changed editorially in February 2012.2NOTETable 1 was editorial
3、ly corrected in May 2013.1. Scope1.1 This procedure covers the determination of aldicarb,carbofuran, oxamyl and methomyl (referred to collectively ascarbamates in this test method) in surface water by directinjection using liquid chromatography (LC) and detected withtandem mass spectrometry (MS/MS).
4、 These analytes are quali-tatively and quantitatively determined by this method. Thismethod adheres to multiple reaction monitoring (MRM) massspectrometry.1.2 This test method has been developed by US EPARegion5 Chicago Regional Laboratory (CRL).1.3 The values stated in SI units are to be regarded a
5、sstandard. No other units of measurement are included in thisstandard.1.4 The Detection Verification Level (DVL) and ReportingRange for the carbamates are listed in Table 1.1.4.1 The DVL is required to be at a concentration at least3 times below the Reporting Limit (RL) and have a signal/noise ratio
6、 greater than 3:1. Fig. 1 displays the signal/noiseratios of the primary single reaction monitoring (SRM) transi-tions and Fig. 2 displays the confirmatory SRM transitions atthe DVLs for the carbamates.1.4.2 The reporting limit is the concentration of the Level 1calibration standard as shown in Tabl
7、e 2 for the carbamates.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior
8、 to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3856 Guide for Management Systems in LaboratoriesEngaged in Analysis o
9、f WaterD3694 Practices for Preparation of Sample Containers andfor Preservation of Organic ConstituentsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisE2554 Practice for Estimating and Monitoring the Uncer-tainty of Test Results of a Test Method i
10、n a SingleLaboratory Using a Control Sample Program2.2 Other Documents:EPA publication SW-846 Test Methods for Evaluating SolidWaste, Physical/Chemical Methods33. Terminology3.1 Definitions:3.1.1 detection verification level (DVL), na concentrationthat has a signal/noise ratio greater than 3:1 and i
11、s at least 3times below the reporting limit (RL).3.1.2 reporting limit (RL), nthe concentration of thelowest-level calibration standard used for quantification.3.1.3 carbamates, nin this test method, aldicarb,carbofuran, oxamyl and methomyl collectively.3.2 Abbreviations:3.2.1 pptparts per trillion,
12、 ng/L1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis forOrganic Substances in Water.Current edition approved Dec. 1, 2009. Published January 2010. DOI: 10.1520/D7600-09E02.2For referenced ASTM st
13、andards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from National Technical Information Service (NTIS), U.S. Depart-ment of C
14、ommerce, 5285 Port Royal Road, Springfield, VA, 22161 or at http:/www.epa.gov/epawaste/hazard/testmethods/index.htm.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.2 NDnon-detect4. Summary of Test Methods4.1 This is a performance-
15、based method and modificationsare allowed to improve performance.4.2 For carbamate analysis, samples are shipped to the labbetween 0C and 6C and analyzed within 7 days of collection.In the lab, the samples are spiked with surrogate, filtered usinga syringe driven Millex HV PVDF filter unit and analy
16、zeddirectly by LC/MS/MS.4.3 Aldicarb, carbofuran, oxamyl, methomyl and 4-bromo-3,5-dimethylphenyl-N-methylcarbamate (BDMC, surrogate)are identified by retention time and two SRM transitions. Thetarget analytes and surrogate are quantitated using the primarySRM transitions utilizing an external calib
17、ration. The finalreport issued for each sample lists the concentration ofaldicarb, carbofuran, oxamyl, methomyl and the BDMC sur-rogate recovery.5. Significance and Use5.1 The N-methyl carbamate (NMC) pesticides: aldicarb,carbaryl, carbofuran, formetanate hydrochloride, methiocarb,methomyl, oxamyl,
18、pirimicarb, propoxur, and thiodicarb havebeen identified by EPA as working through a common mecha-nism. They affect the nervous system by reducing the ability ofthe enzyme cholinesterase. Cholinesterase inhibition was theprimary toxicological effect of regulatory concern to EPA inassessing the NMCs
19、food, drinking water and residential risks.In most of the country, NMC residues in drinking watersources are at levels that are not likely to contribute substan-tially to the multi-pathway cumulative exposure. Shallowprivate wells extending through highly permeable soils intoshallow, acidic ground w
20、ater represent what the EPA believesto be the most vulnerable drinking water.45.2 This method has been investigated for use with reagentand surface water for the selected carbamates: aldicarb,carbofuran, oxamyl and methomyl.6. Interferences6.1 Method interferences may be caused by contaminants insol
21、vents, reagents, glassware and other apparatus producingdiscrete artifacts or elevated baselines. All of these materialsare demonstrated to be free from interferences by analyzinglaboratory reagent blanks under the same conditions assamples.6.2 All glassware is washed in hot water with a detergent,r
22、insed in hot water followed by distilled water. The glasswareis then dried and heated in an oven at 250C for 15 to 30minutes. All glassware is subsequently cleaned with acetone,then methanol.6.3 All reagents and solvents should be pesticide residuepurity or higher to minimize interference problems.6
23、.4 Matrix interferences may be caused by contaminantsthat are co-extracted from the sample. The extent of matrixinterferences can vary considerably from sample source de-pending on variations of the sample matrix.7. Apparatus7.1 LC/MS/MS System7.1.1 Liquid Chromatography (LC) SystemAcomplete LCsyste
24、m is needed in order to analyze samples.5Asystem that iscapable of performing at the flows, pressures, controlledtemperatures, sample volumes and requirements of the stan-dard may be used.7.1.2 Analytical Column-WatersXBridge C18, 150 mm 2.1 mm, 3.5 m particle size, or equivalent.7.1.3 Tandem Mass S
25、pectrometer (MS/MS) SystemAMS/MS system capable of MRM analysis.6A system that iscapable of performing at the requirements in this standard maybe used.7.2 Filtration Device7.2.1 Hypodermic syringeAlock tip glass syringe capableof holding a Millex HV Syringe Driven Filter Unit PVDF 0.45m (Millipore C
26、orporation, Catalog # SLHV033NS) or similarmay be used.7.2.1.1 A25-mL lock tip glass syringe size is recommendedsince a 25-mL sample size is used in this test method.7.2.2 FilterMillex HV Syringe Driven Filter Unit PVDF0.45 m (Millipore Corporation, Catalog # SLHV033NS) orsimilar may be used.8. Reag
27、ents and Materials8.1 Purity of ReagentsHigh-performance liquid chroma-tography (HPLC) pesticide residue analysis and spectropho-tometry grade chemicals shall be used in all tests. Unlessindicated otherwise, it is intended that all reagents shallconform to the Committee on Analytical Reagents of the
28、American Chemical Society.7Other reagent grades may beused provided they are first determined to be of sufficientlyhigh purity to permit their use without affecting the accuracy ofthe measurements.4Additional information about carbamate pesticides can be found on the Internetat http:/www.epa.gov (20
29、09).5A Waters Alliance High Performance Liquid Chromatography (HPLC) Systemwas used to develop this test method. The multi-laboratory study included Agilent,Thermo Electron and Waters LC systems.6A Waters Quattro micro API mass spectrometer was used to develop this testmethod. The multi-laboratory s
30、tudy included Agilent, Applied Biosystems, ThermoElectron, Varian and Waters mass spectrometers.7Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual St
31、andards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Detection Verification Level and Reporting RangeAnalyte DVL (ng/L) Reporting Range (g/L)Aldicarb 100 1100Carbofur
32、an 100 1100Oxamyl 100 1100Methomyl 100 1100 Measurement editorially corrected.D7600 0922FIG. 1 Example Primary SRM Chromatograms Signal/Noise RatiosFIG. 2 Example Confirmatory SRM Chromatograms Signal/Noise RatiosD7600 09238.2 Purity of WaterUnless otherwise indicated, referencesto water shall be un
33、derstood to mean reagent water conformingto Type 1 of Specification D1193. It must be demonstrated thatthis water does not contain contaminants at concentrationssufficient to interfere with the analysis.8.3 GasesUltrapure nitrogen and argon.8.4 Acetonitrile (CAS # 75-05-8).8.5 Methanol (CAS # 67-56-
34、1).8.6 Acetone (CAS # 67-64-1).8.7 Ammonium acetate (CAS # 631-61-8).8.8 Ammonium hydroxide (Concentrated, CAS # 1336-21-6).8.9 Aldicarb (CAS # 116-06-3).8.10 Carbofuran (CAS # 1563-66-2).8.11 Oxamyl (CAS # 23135-22-0).8.12 Methomyl (CAS # 16752-77-5).8.13 4-Bromo-3,5-dimethylphenyl-N-methylcarbamat
35、e(BDMC, CAS # 672-99-1).8.13.1 BDMC is used as a surrogate in this standard.9. Hazards9.1 Normal laboratory safety applies to this method. Ana-lysts should wear safety glasses, gloves, and lab coats whenworking in the lab. Analysts should review the Material SafetyData Sheets (MSDS) for all reagents
36、 used in this method.10. Sampling10.1 SamplingGrab samples must be collected in 25-mLpre-cleaned amber glass bottles with Teflon-lined caps demon-strated to be free of interferences. This test method requires a25-mL sample size per analysis. Conventional sampling prac-tices should be followed. Refer
37、 to Guide D3856 and PracticesD3694.10.2 PreservationStore samples between 0C and 6Cfrom the time of collection until analysis. Analyze the samplewithin 7 days of collection.11. Preparation of LC/MS/MS11.1 LC Chromatograph Operating Conditions5:11.1.1 Injection volumes of all calibration standards an
38、dsamples are 100 L. The first sample analyzed after thecalibration curve is a blank to ensure there is no carry-over.Thegradient conditions for the liquid chromatograph are shown inTable 3.11.1.2 TemperaturesColumn, 30C; Samplecompartment, 15C.11.1.3 Seal WashSolvent: 50 % Acetonitrile/50 % Water;Ti
39、me: 5 minutes.11.1.4 Needle WashSolvent: 50 % Acetonitrile/50 % Wa-ter; Normal wash, approximately 13 second wash time.11.1.5 Autosampler PurgeThree loop volumes.11.1.6 Specific instrument manufacturer wash/purge speci-fications should be followed in order to eliminate samplecarry-over in the analys
40、is of carbamates.11.2 Mass Spectrometer Parameters6:11.2.1 In order to acquire the maximum number of datapoints per SRM channel while maintaining adequatesensitivity, the tune parameters may be optimized according toyour instrument. Each peak requires at least 10 scans per peakfor adequate quantitat
41、ion. This standard contains only onesurrogate and four target compounds. The MRM experimentwindows were set to acquire methomyl and oxamyl in oneexperiment window while aldicarb, carbofuran and BDMC arein their individual MRM experiment windows. This is requiredbecause the chromatographic resolution
42、 separating oxamyl andmethomyl was not achieved. Variable parameters regardingretention times, SRM Transitions and cone and collisionenergies are shown in Table 4.The instrument is set in the Electrospray (+) positive setting.Capillary Voltage: 3.5 kVCone: Variable depending on analyte (Table 4)Extr
43、actor: 2 VoltsRF Lens: 0.2 VoltsSource Temperature: 120CDesolvation Temperature: 300CDesolvation Gas Flow: 500 L/hrCone Gas Flow: 25 L/hrLow Mass Resolution 1: 14.5High Mass Resolution 1: 14.5Ion Energy 1: 0.5Entrance Energy: 1Collision Energy: Variable depending on analyte (Table 4)Exit Energy: 2Lo
44、w Mass Resolution 2: 15High Mass resolution 2: 15Ion Energy 2: 0.5Multiplier: 650Gas Cell Pirani Gauge: 3.3 103TorrInter-Channel Delay: 0.02 secondsInter-Scan Delay: 0.1 secondsRepeats: 1Span: 0 DaltonsDwell: 0.1 SecondsTABLE 2 Concentrations of Calibration Standards (PPB)Analyte/Surrogate LV 1 LV 2
45、 LV 3 LV 4 LV 5 LV 6Aldicarb 1 5 10 25 50 100Carbofuran 1 5 10 25 50 100Oxamyl 1 5 10 25 50 100Methomyl 1 5 10 25 50 100BDMC (Surrogate) 2 10 20 50 100 200TABLE 3 Gradient Conditions for Liquid ChromatographyTime(min)Flow(L/min)PercentCH3CNPercent 95 %Water/ 5 %CH3CNPercent50 mmolarNH4OAc/NH4OHin 95
46、 % Water/5 %CH3CN0 300 0 95 52 300 0 95 54 300 30 65 56 300 35 60 58 300 35 60 510 300 75 20 511.5 300 75 20 512 300 95 0 518 300 95 0 520 300 0 95 523 300 0 95 5D7600 092412. Calibration and Standardization12.1 The mass spectrometer must be calibrated per manu-facturer specifications before analysi
47、s. In order that analyticalvalues obtained using this test method are valid and accuratewithin the confidence limits of the test method, the followingprocedures must be followed when performing the test method.12.2 Calibration and StandardizationTo calibrate theinstrument, analyze six calibration st
48、andards containing the sixconcentration levels of the carbamates and BDMC surrogateprior to analysis as shown in Table 2. A calibration stockstandard solution is prepared from standard materials orpurchased as certified solutions. Stock standard solution A(Level 6) containing aldicarb, carbofuran, o
49、xamyl, methomyland BDMC is prepared at Level 6 concentration and aliquots ofthat solution are diluted to prepare Levels 1 through 5. Thefollowing steps will produce standards with the concentrationvalues shown in Table 2. The analyst is responsible forrecording initial component weights carefully when workingwith pure materials and correctly carrying the weights throughthe dilution calculations.12.2.1 Prepare stock standard solution A (Level 6) byadding to a 100-mL volumetric flask individual methanolsolutions of the follow
