1、Designation: D7979 17Standard Test Method forDetermination of Per- and Polyfluoroalkyl Substances inWater, Sludge, Influent, Effluent and Wastewater by LiquidChromatography Tandem Mass Spectrometry (LC/MS/MS)1This standard is issued under the fixed designation D7979; the number immediately following
2、 the designation indicates the year oforiginal adoption 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.1. Scope1.1 This procedure covers
3、 the determination of selected per-and polyfluoroalkyl substances (PFASs) in a water matrixusing liquid chromatography (LC) and detection with tandemmass spectrometry (MS/MS). These analytes are qualitativelyand quantitatively determined by this method. This methodadheres to a technique known as sel
4、ected reaction monitoring(SRM) or sometimes referred to as multiple reaction monitor-ing (MRM). This is not a drinking water method, performanceof this test method has not been evaluated on drinking watermatrices.1.2 The Method Detection Limit (MDL)2and ReportingRange3for the target analytes are lis
5、ted in Table 1. The targetconcentration for the reporting limit for this test method was 10ng/Lfor most of the target analytes at the time of development.1.2.1 The reporting limit in this test method is the minimumvalue below which data are documented as non-detects. Thereporting limit may be lowere
6、d providing your lab meets theminimum performance requirements of this test method at thelower concentrations, this method is performance based andmodifications are allowed to improve performance. Analytedetections between the method detection limit and the report-ing limit are estimated concentrati
7、ons and are not reportedfollowing this test method. In most cases, the reporting limit isthe concentration of the Level 1 calibration standard as shownin Table 4 for the PFASs after taking into account the 50 %dilution with methanol. It is above the Level 1 calibrationconcentration for FHEA and FOEA
8、, these compounds can beidentified at the Level 1 concentration but the standard devia-tion among replicates at this lower spike level resulted in ahigher reporting limit.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 T
9、his 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, health and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 T
10、his international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trad
11、e (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:4D1129 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
12、Analysis of WaterD3694 Practices for Preparation of Sample Containers andfor Preservation of Organic ConstituentsD4841 Practice for Estimation of Holding Time for WaterSamples Containing Organic and Inorganic ConstituentsD5847 Practice for Writing Quality Control Specificationsfor Standard Test Meth
13、ods for Water AnalysisE2554 Practice for Estimating and Monitoring the Uncer-tainty of Test Results of a Test Method Using ControlChart Techniques1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis f
14、orOrganic Substances in Water.Current edition approved July 15, 2017. Published August 2017. Originallyapproved in 2015. Last previous edition approved in 2016 as D7979 16. DOI:10.1520/D7979-17.2The MDL is determined following the Code of Federal Regulations (CFR) , 40CFR Part 136, Appendix B utiliz
15、ing dilution and filtration. 5 mL sample of waterwas utilized. A detailed process determining the MDL is explained in the referenceand is beyond the scope of this test method to be explained here.3Reporting range concentration is calculated from Table 4 concentrationsassuming a 30 L injection of the
16、 Level 1 calibration standard for PFASs, and thehighest level calibration standard with a 10 mLfinal extract volume ofa5mLwatersample. Volume variations will change the reporting limit and ranges.4For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
17、 serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accorda
18、nce with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.12.2 Other Standards:5EPAPublicatio
19、n SW-846, Test Methods for Evaluating SolidWaste, Physical/Chemical MethodsCode of Federal Regulations 40 CFR Part 136, Appendix B3. 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 per
20、- and polyfluoroalkyl substances, nin this testmethod, 11 perfluoroalkyl carboxylic acids, 3perfluoroalkylsulfonates, Decafluoro-4-(pentafluoroethyl)cyclohexanesulfonate and 6 fluorotelomeracids listed in Table 1 collectively (not including any masslabeled surrogates).3.2.2 reporting limit, nthe min
21、imum concentration belowwhich data are documented as non-detects.3.3 Acronyms:3.3.1 CCC, nContinuing Calibration Check3.3.2 FTAs and FTUAs, nFluorotelomer and UnsaturatedFluorotelomer Acids3.3.2.1 FDEA, n2-perfluorodecyl ethanoic acid3.3.2.2 FHEA, n2-perfluorohexyl ethanoic acid3.3.2.3 FHpPA, n3-per
22、fluoroheptyl propanoic acid3.3.2.4 FHUEA, n2H-perfluoro-2-octenoic acid3.3.2.5 FOEA, n2-perfluorooctyl ethanoic acid3.3.2.6 FOUEA, n2H-perfluoro-2-decenoic acid3.3.3 IC, nInitial Calibration3.3.4 LC, nLiquid Chromatography3.3.5 LCS/LCSD, nLaboratory Control Sample/Laboratory Control Sample Duplicate
23、3.3.6 MDL, nMethod Detection Limit3.3.7 MeOH, nMethanol3.3.8 mM, nmillimolar,110-3moles/L3.3.9 MPFAC, nIsotopically labeled Perfluoroalkylcar-boxylates3.3.9.1 MPFBA, n13C4-Perfluorobutanoate3.3.9.2 MPFDA, n13C2-Perfluorodecanoate3.3.9.3 MPFDoA, n13C2-Perfluorododecanoate3.3.9.4 MPFHxA, n13C2-Perfluo
24、rohexanoate3.3.9.5 MPFNA, n13C5-Perfluorononanoate3.3.9.6 MPFOA, n13C4-Perfluorooctanoate3.3.9.7 MPFUnA, n13C2-Perfluoroundecanoate3.3.10 MPFAlS, nIsotopically labeled Perfluoroalkylsul-fonates3.3.10.1 MPFHxS, n18O2-Perfluorohexylsulfonate3.3.10.2 MPFOS, n13C4-Perfluorooctylsulfonate3.3.11 MRM, nMul
25、tiple Reaction Monitoring3.3.12 MS/MSD, nMatrix Spike/Matrix Spike Duplicate3.3.13 NA, adjNot Available3.3.14 ND, nnon-detect3.3.15 P however, this test method is intended to be performancebased and alternative operating conditions can be used toperform this method provided data quality objectives a
26、reattained.4.2 For PFASs analysis, samples are shipped to the lab at atemperature between 0C and 6C and analyzed within 28 daysof collection. A sample (5 mL) is collected in a polypropylenetube in the field and that total sample is processed in order tolimit target analyte loss due to sample manipul
27、ation and lossesto surfaces, spiked with surrogates (all samples) and targetPFASs (laboratory control and matrix spike samples) and handshaken for 2 minutes after adding 5 mL of methanol. Thesamples are then filtered through a polypropylene filter unit.Acetic acid (10 L) is added to all the samples
28、to adjust to pH3 and analyzed by LC/MS/MS. For 5 mL sludge samples; 5mL methanol is added, adjusted to pH 9 (adding 20 l ofammonium hydroxide), hand shaken, filtered, acidified to pH3 (50 L acetic acid) and then analyzed by LC/MS/MS.NOTE 1Sludge in this method is defined as sewage sample containingb
29、etween 0.1 and 2% solids based upon a sample by weight.NOTE 2Since surface binding of target compounds may bias data, itis best to collect a 5.0 mLsample in a graduated 15 mLpolypropylene BDFalcon tube in the field so that the whole sample is processed in the lab(NOALIQUOTING). Once this 5.0 mLsampl
30、e is spiked according to thisStandard and methanol is added, it is then thoroughly shaken andtransferred to a new 15 mL polypropylene tube during filtration. In orderto have accurate volumes, the weight of the 15 mL polypropylene BDFalcon tube may be taken before and after sampling in order to obtai
31、n anexact volume. The density of water is assumed to be 1.0 g/mL unless theexact density of the water sample is known, then that conversion shouldbe used.4.3 Most of the PFASs are identified by comparing the SRMtransition and its confirmatory SRM transition if correlated tothe known standard SRM tra
32、nsition (Table 3) and quantitatedutilizing an external calibration. The surrogates and somePFASs (PFPeA, PFBA, FOUEA and FHUEA) only utilize oneSRM transition due to a less sensitive or non-existent second-ary SRM transition. As an additional quality-control measure,isotopically labeled PFASs surrog
33、ates (listed in 12.4) recover-ies are monitored. There is no correction to the data based uponsurrogate recoveries. The final report issued for each samplelists the concentration of PFASs, if detected, or as a non-detectat the RL, if not detected, in ng/L and the surrogate recoveries.5. Significance
34、 and Use5.1 PFASs are widely used in various industrial and com-mercial products; they are persistent, bio-accumulative, andubiquitous in the environment. PFASs have been reported toexhibit developmental toxicity, hepatotoxicity,immunotoxicity, and hormone disturbance. A draft Toxicologi-cal Profile
35、 for Perfluoroalkyls from the U.S. Department ofHealth and Human Services is available.6PFASs have beendetected in soils, sludges, surface, and drinking waters. Hence,there is a need for quick, easy, and robust method to determinethese compounds at trace levels in water matrices for under-standing o
36、f the sources and pathways of exposure.5.2 This method has been investigated for use with reagent,surface, sludge and wastewaters for selected PFASs. Thismethod has not been evaluated on drinking water matrices.6. Interferences6.1 All glassware is washed in hot water (typically 45C)with detergent an
37、d rinsed in hot water followed by distilledwater. The glassware is then dried and heated in an oven(typically at 105C) for 15 to 30 minutes. All glassware issubsequently rinsed with methanol or acetonitrile.6.2 All reagents and solvents should be pesticide residuepurity or higher to minimize interfe
38、rence problems. The use ofPFASs containing caps shall be avoided.6.3 Matrix interferences may be caused by contaminants inthe sample. The extent of matrix interferences can varyconsiderably depending on variations of the sample matrices.6.4 Contaminants have been found in reagents, glassware,tubing,
39、 glass disposable pipettes, filters, degassers and otherapparatus that release PFASs. All of these materials andsupplies are routinely demonstrated to be free from interfer-ences by analyzing laboratory reagent blanks under the sameconditions as the samples. If found, measures should be takento remo
40、ve the contamination or data should be qualified,background subtraction of blank contamination is not allowed.6.5 The Liquid Chromatography system used shouldconsist, as much as practical, of sample solution or eluentcontacting components free of PFASs of interest.6.6 Polyethylene LC vial caps or an
41、y other target analytefree vial caps should be used.6.7 Polyethylene disposable pipettes or target analyte freepipettes should be used. All disposable pipettes should bechecked for release of target analytes of interest.6.8 Degassers are important to continuous LC operation andmost commonly are made
42、 of fluorinated polymers. To enableuse, an isolator column should be placed after the degasser andprior to the sample injection valve to separate the PFASs in thesample from the PFASs in the LC system.7. Apparatus7.1 LC/MS/MS System:7.1.1 Liquid Chromatography System7A complete LCsystem is required
43、in order to analyze samples, this shouldinclude a sample injection system, a solvent pumping system6A Draft Toxicological Profile for Perfluoroalkyls can be found at: http:/www.atsdr.cdc.gov/toxprofiles/tp.asp?id=1117 Samplecompartment, 15C.11.2.3 Seal WashSolvent: 60 % acetonitrile/40 %2-propanol;
44、Time: 5 minutes.11.3 Mass Spectrometer Parameters:11.3.1 To acquire the maximum number of data points perSRM channel while maintaining adequate sensitivity, the tuneparameters may be optimized according to your instrument.Each peak requires at least 10 scans per peak for adequatequantitation. This t
45、est method contains nine surrogates, whichare select isotopically labeled PFASs, and 21 PFASs whichwere split up into eighteen MRM acquisition functions tooptimize sensitivity. Variable parameters regarding retentiontimes, SRM transitions, and cone and collision energies areshown in Table 3. Mass sp
46、ectrometer parameters used in thedevelopment of this method are listed below:The instrument is set in the Electrospray negative source setting.Capillary Voltage: 0.75 kVCone: Variable depending on analyteSource Temperature: 150CDesolvation Gas Temperature: 450CDesolvation Gas Flow: 800 L/hrCone Gas
47、Flow: 200 L/hrCollision Gas Flow: 0.15 mL/minLow Mass Resolution 1: 2.6High Mass Resolution 1: 14Ion Energy 1: 1Entrance Energy: 1Collision Energy: Variable depending on analyteExit Energy: 1Low Mass Resolution 2: 2.5High Mass Resolution 2: 14Ion Energy 2: 3Gain: 1.0Multiplier: 511.1Inter-Scan Delay
48、: 0.004 seconds14PFAS surrogates from Wellington Laboratories Inc. or equivalent, have beenfound suitable for use.15Guides to help determine holding times can be found at: http:/www.epa.gov/esd/cmb/research/bs_033cmb06.pdf (2014) and Practice D4841.D7979 17612. Calibration and Standardization12.1 Th
49、e mass spectrometer shall be calibrated as in accor-dance with manufacturers specifications before analysis. Ana-lytical values satisfying test method criteria have beenachieved using the following procedures. Prepare all solutionsin the lab using Class A volumetric glassware.12.2 Calibration and StandardizationTo calibrate theinstrument, analyze nine calibration standards containing thePFASs and surrogates prior to analysis as shown in Table 4.Calibration stock standard solution is prepared from the targetand surrogate spike
