1、Designation: D7600 16Standard 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 o
2、r, 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.1. Scope1.1 This procedure covers the determination of aldicarb,carbofuran, oxamyl and met
3、homyl (referred to collectively ascarbamates in this test method) in surface water by directinjection using liquid chromatography (LC) and detected withtandem mass spectrometry (MS/MS). These analytes are quali-tatively and quantitatively determined by this test method. Thistest method adheres to mu
4、ltiple reaction monitoring (MRM)mass spectrometry.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 asstandard. No other units of measurement are included in thisstandard.1.4 The Detection Verification Leve
5、l (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 greater than 3:1. Fig. 1 displays the signal/noiseratios of the primary single reaction monitoring (SRM)
6、 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 Table 2 for the carbamates.1.5 This standard does not purport to address all of thesafety concerns, if any, a
7、ssociated 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 to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification
8、 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 of WaterD3694 Practices for Preparation of Sample Containers andfor Preservation of Organic ConstituentsD5
9、847 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 Using ControlChart Techniques2.2 Other Documents:3EPA publication SW-846 Test Methods for Evaluating Solid
10、Waste, Physical/Chemical Methods3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTerminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 detection verification level, DVL, na concentrationthat has a signal/noise ratio greater than 3:1 and
11、 is at least 3times below the reporting limit (RL).3.2.2 carbamates, nin this test method, aldicarb,carbofuran, oxamyl and methomyl collectively.3.2.3 independent reference material, IRM, na material ofknown purity and concentration obtained either from the1This test method is under the jurisdiction
12、 of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis forOrganic Substances in Water.Current edition approved Feb. 1, 2016. Published May 2016. Originallyapproved in 2009. Last previous edition approved in 2009 as D7600 093. DOI:10.1520/D7600-1
13、6.2For referenced ASTM standards, 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 (NTI
14、S), U.S. Depart-ment of Commerce, 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 States1National Institute of Standards andTechnology
15、 (NIST) or otherreputable supplier. The IRM shall be obtained from a differentlot of material than is used for calibration3.3 Acronyms:3.3.1 CCC, nContinuing Calibration Check3.3.2 IC, nInitial Calibration3.3.3 LC, nLiquid Chromatography3.3.4 LCS/LCSD, nLaboratory Control Sample/Laboratory Control S
16、ample Duplicate3.3.5 MDL, nMethod Detection Limit3.3.6 MeOH, nMethanol3.3.7 mM, nmillimolar,110-3moles/L3.3.8 MRM, nMultiple Reaction Monitoring3.3.9 MS/MSD, nMatrix Spike/Matrix Spike Duplicate3.3.10 NA, adjNot Available3.3.11 ND, nnon-detect3.3.12 P Samplecompartment, 15C.6AWaters (a trademark of
17、the Waters Corporation, Milford, MA) XBridge C18,150 mm 2.1 mm, 3.5 m particle size, or equivalent, has been found suitable foruse.7A Waters Quattro micro API mass spectrometer (a trademark of the WatersCorporation, Milford, MA), or equivalent, was found suitable for use. Themulti-laboratory study i
18、ncluded Applied Biosystems and Waters mass spectrom-eters.8A Millex HV Syringe Driven Filter Unit PVDF 0.45 m (MilliporeCorporation, Catalog # SLHV033NS; a trademark of the Waters Corporation,Milford, MA) has been found suitable for use for this test method, any filter unitmay be used that meets the
19、 performance of this test method may be used.9Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, D
20、orset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 2 Concentrations of Calibration Standards (PPB)Analyte/Surrogate LV 1 LV 2 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
21、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 % 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
22、 511.5 300 75 20 512 300 95 0 518 300 95 0 520 300 0 95 523 300 0 95 5D7600 16411.1.3 Seal WashSolvent: 50 % Acetonitrile/50 % Water;Time: 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.
23、1.6 Specific instrument manufacturer wash/purge speci-fications should be followed in order to eliminate samplecarry-over in the analysis of carbamates.11.2 Mass Spectrometer Parameters:711.2.1 In order to acquire the maximum number of datapoints per SRM channel while maintaining adequatesensitivity
24、, the tune parameters may be optimized according toyour instrument. Each peak requires at least 10 scans per peakfor adequate quantitation. This standard contains only onesurrogate and four target compounds. The MRM experimentwindows were set to acquire methomyl and oxamyl in oneexperiment window wh
25、ile aldicarb, carbofuran and BDMC arein their individual MRM experiment windows. This is requiredbecause the chromatographic resolution separating oxamyl andmethomyl was not achieved. Variable parameters regardingretention times, SRM Transitions and cone and collisionenergies are shown in Table 4.Th
26、e instrument is set in the Electrospray (+) positive setting.Capillary Voltage: 3.5 kVCone: Variable depending on analyte (Table 4)Extractor: 2 VoltsRF Lens: 0.2 VoltsSource Temperature: 120CDesolvation Temperature: 300CDesolvation Gas Flow: 500 L/hrCone Gas Flow: 25 L/hrLow Mass Resolution 1: 14.5H
27、igh Mass Resolution 1: 14.5Ion Energy 1: 0.5Entrance Energy: 1Collision Energy: Variable depending on analyte (Table 4)Exit Energy: 2Low 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:
28、 0.1 secondsRepeats: 1Span: 0 DaltonsDwell: 0.1 Seconds12. Calibration and Standardization12.1 The mass spectrometer must be calibrated per manu-facturer specifications before analysis. In order that analyticalvalues obtained using this test method are valid and accuratewithin the confidence limits
29、of the test method, the followingprocedures must be followed when performing the test method.12.2 Calibration and StandardizationTo calibrate theinstrument, analyze six calibration standards containing the sixconcentration levels of the carbamates and BDMC surrogateprior to analysis as shown in Tabl
30、e 2. A calibration stockstandard solution is prepared from standard materials orpurchased as certified solutions. Stock standard solution A(Level 6) containing aldicarb, carbofuran, oxamyl, methomyland BDMC is prepared at Level 6 concentration and aliquots ofthat solution are diluted to prepare Leve
31、ls 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 stoc
32、k standard solution A (Level 6) byadding to a 100-mL volumetric flask individual methanolsolutions of the following: 50 L of aldicarb, carbofuran,oxamyl and methomyl each at 0.2 g/L and 50 L of BDMC at0.4 g/L, dilute to 100 mL with 90% water/10% methanol. Thepreparation of the Level 6 standard can b
33、e accomplished usingdifferent volumes and concentrations of stock solutions as isaccustomed in the individual laboratory. Depending on stockconcentrations prepared, the solubility at that concentrationwill have to be ensured.12.2.2 Aliquots of Solution A are then diluted with 90 %water/10 % methanol
34、 to prepare the desired calibration levelsin 2-mL amber glass LC vials. The calibration vials must beused within 24 hours to ensure optimum results. Stock calibra-tion standards are routinely replaced every 7 days if notpreviously discarded for quality control failure. Calibrationstandards are not f
35、iltered.12.2.3 Inject each standard and obtain a chromatogram foreach one. An external calibration technique is used monitoringthe primary and confirmatory SRM transition of each analyte.Calibration software is utilized to conduct the quantitation ofTABLE 4 Retention Times, SRM Ions, and Analyte-Spe
36、cific Mass Spectrometer ParametersAnalyte Primary/ Confirmatory Retentiontime (min)Cone Voltage(Volts)Collision Energy (eV) SRM Mass Transition(Parent Product)Collision Energy(eV)AldicarbPrimary11.0010 7 208.2 115.92.12Confirmatory 10 15 208.2 88.7CarbofuranPrimary12.8527 12 222.2 165.21.20Confirmat
37、ory 27 20 222.2 123OxamylPrimary8.2515 8 237.2 71.62.38Confirmatory 15 8 237.2 89.8MethomylPrimary8.4517 8 163.1 87.71.58Confirmatory 17 8 163.1 105.8BDMC (Surrogate)Primary14.5025 24 258.1 1221.31Confirmatory 25 9 258.1 201.2D7600 165the target analytes and surrogate using the primary SRMtransition
38、. The ratios of the primary/confirmatory SRM transi-tion area counts are given in Table 4. These are given asinformative and will vary depending on the individual tuningconditions. The primary/confirmatory SRM transition arearatio must be within 30 % of the individual labs acceptedprimary/confirmato
39、ry SRM transition area ratio. The primarySRM transition of each analyte is used for quantitation and theconfirmatory SRM transition for confirmation. This givesadded confirmation by isolating the parent ion, fragmenting itinto two product ions, and relating it to the retention time in thecalibration
40、 standard.12.2.4 The calibration software manual should be consultedto use the software correctly. The quantitation method is set asan external calibration using the peak areas in ppt or ppb unitsas long as the analyst is consistent. Concentrations may becalculated using the data system software to
41、generate linearregression or quadratic calibration curves. Forcing the calibra-tion through the origin is not recommended.12.2.5 Linear calibration may be used if the coefficient ofdetermination, r2, is 0.98 for the analyte. The point of originis excluded and a fit weighting of 1/X is used in order
42、to givemore emphasis to the lower concentrations. If one of thecalibration standards other than the high or low point causesthe r2of the curve to be 0.99 for the analyte. The point oforigin is excluded and a fit weighting of 1/X is used in order togive more emphasis to the lower concentrations. If o
43、ne of thecalibration standards causes the curve to be 0.99. Inthis event, the reporting range must be modified to reflect thischange.12.2.7 The retention time window of the SRM transitionsmust be within 5 % of the retention time of the analyte in amidpoint calibration standard. If this is not the ca
44、se, re-analyzethe calibration curve to determine if there was a shift inretention time during the analysis and the sample needs to bere-injected. If the retention time is still incorrect in the sample,refer to the analyte as an unknown.12.2.8 A midpoint calibration check standard must be ana-lyzed a
45、t the end of each batch of 20 samples or within 24 hoursafter the initial calibration curve was generated. This endcalibration check should be the same calibration standard thatwas used to generate the initial curve. The results from the endcalibration check standard must have a percent deviation le
46、ssthan 30 % from the calculated concentration for the targetanalytes and surrogate. If the results are not within thesecriteria, the problem must be corrected and either: all samplesin the batch must be re-analyzed against a new calibrationcurve, or the affected results must be qualified with anindi
47、cation that they do not fall within the performance criteriaof the test method. If the analyst inspects the vial containingthe end calibration check standard and notices that the sampleevaporated affecting the concentration, a new end calibrationcheck standard may be made and analyzed. If this new e
48、ndcalibration check standard has a percent deviation less than30 % from the calculated concentration for the target analytesand surrogate the results may be reported unqualified.12.3 All samples are prepared using Class A glass volumet-ric glassware. The sample volume used throughout this testmethod
49、 is 25 mL. Every sample, the entire 25 mL volume, isfiltered through the filtration device described in Section 7.2only after all required spiking solutions are added and mixedthroughout the sample.12.3.1 Anew filter unit is used for each sample. The syringemust be cleaned between each filtration. It is the analystsresponsibility to ensure that the syringe is clean. A possibleway of cleaning the syringe between filtrations is first byrinsing with at least 5 syringe volumes of water, followed by atleast 3 volumes of acetone, then 3 volumes of met
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