1、Designation: D7731 17Standard Test Method forDetermination of Dipropylene Glycol Monobutyl Ether andEthylene Glycol Monobutyl Ether in Sea Water by LiquidChromatography/Tandem Mass Spectrometry (LC/MS/MS)1This standard is issued under the fixed designation D7731; the number immediately following the
2、 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 test method covers t
3、he determination of dipropyl-ene glycol monobutyl ether (DPGBE) and ethylene glycolmonobutyl ether (EGBE) in sea water by direct injection usingliquid chromatography (LC) and detection with tandem massspectrometry (MS/MS). These analytes are qualitatively andquantitatively determined by this test me
4、thod. This test methodadheres to selected reaction monitoring (SRM) mass spectrom-etry.1.2 The detection verification level (DVL) and reportingrange for DPGBE and EGBE are listed in Table 1.1.2.1 The DVL is required to be at a concentration at least3 times below the reporting limit (RL) and have a s
5、ignal/noiseratio greater than 3:1. Fig. 1 and Fig. 2 display the signal/noiseratio of the single reaction monitoring (SRM) transition.1.2.2 The reporting limit is the concentration of the Level 1calibration standard as shown in Table 4 for DPGBE andEGBE, taking into account the 20 % sample preparati
6、ondilution factor.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 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
7、 to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Pr
8、inciples for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for
9、Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on Water2.2 Other Standards:3EPA Publication SW-846 Test Methods for Evaluating SolidWaste, Physical/Chemical Methods3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTerminology
10、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 is at least 3times below the reporting limit (RL).3.2.2 reporting limit, RL, nthe concentration of thelowest-level calibration standard
11、 used for quantification.3.2.2.1 DiscussionIn this test method, a 20-mL samplealiquot is diluted to a 25-mL final volume after thoroughlyrinsing the collection vial with acetonitrile for quantitativetransfer. In this case, the lowest calibration level of 100 ppb forEGBE would allow for a reporting l
12、imit of 125 ppb to beachieved.3.3 Abbreviations:3.3.1 mMmillimolar,1103moles/L3.3.2 NAno addition3.3.3 NDnon-detect3.3.4 ppbparts per billion, g/L3.3.5 pptparts per trillion, ng/L1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommitte
13、e D19.06 on Methods forAnalysis forOrganic Substances in Water.Current edition approved Dec. 15, 2017. Published January 2018. Originallyapproved in 2011. Last previous edition approved in 2011 as D7731 111. DOI:10.1520/D7731-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, o
14、rcontact 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), 5301 ShawneeRd., Alexandria, VA 22312, http:/www.ntis.gov.Copyright A
15、STM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International St
16、andards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.14. Summary of Test Method4.1 This is a performance-based method, and modificationsare allowed to improve performance.4.2 For DPGBE and EGBE analysis, samples are shipped tothe lab
17、between 0C and 6C and analyzed within 5 days ofcollection. The DOW MSDS sheet on DOWANOL*DPNBglycol ether (DPGBE) (Issue Date: 06/18/2010) lists that thematerial is readily biodegradable. The Organisation for Eco-nomic Co-Operation and Development (OECD) 302BTest lists96 % biodegradation in 28 days.
18、4.3 In the lab, the entire collected 20-mL sample is spikedwith surrogate and brought to a volume of 25 mL withacetonitrile. This prepared sample is then filtered using asyringe driven filter unit, and analyzed by LC/MS/MS. Ifvisible oil is present, the prepared sample is allowed to settleresulting
19、in an oil layer at the top of the 25-mL solution. Aportion of the aqueous (bottom) layer is filtered, leaving the oillayer behind, through a syringe driven filter assembly andanalyzed by LC/MS/MS.4.4 DPGBE, EGBE, and surrogate are identified by reten-tion time and one SRM transition. The target anal
20、ytes andsurrogate are quantitated using the SRM transitions utilizing anexternal calibration. The final report issued for each samplelists the concentration of DPGBE, EGBE, and the surrogaterecovery.5. Significance and Use5.1 DPGBE and EGBE have a variety of residential andindustrial applications su
21、ch as cleaning formulations, surfacecoatings, inks, and cosmetics. These analytes may be releasedinto the environment at levels that may be harmful to aquaticlife.5.2 This test method has been investigated for use withreagent and sea water.6. Interferences6.1 Method interferences may be caused by co
22、ntaminants insolvents, 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 w
23、ith detergent andrinsed in hot water followed by distilled water. Detergentscontaining DPGBE or EGBE must not be used. The glasswareis then dried and heated in an oven at 250C for 15 to 30minutes. All glassware is subsequently cleaned with acetonefollowed by methanol.6.3 All reagents and solvents sh
24、ould be pesticide residuepurity or higher to minimize interference problems.6.4 Matrix interferences may be caused by contaminants inthe sample. The extent of matrix interferences can varyconsiderably from sample source depending on variations ofthe sample matrix.7. Apparatus7.1 LC/MS/MS System:7.1.
25、1 Liquid Chromatography SystemA complete LC sys-tem is needed in order to analyze samples.4Any system that iscapable of performing at the flows, pressures, controlledtemperatures, sample volumes, and requirements of the stan-dard may be used.7.1.2 Analytical ColumnWaters XBridge,52.1 150 mm,3.5-m pa
26、rticle size was used to develop this test method. Anycolumn that achieves baseline resolution of these analytes maybe used. Baseline resolution simplifies data analysis and canreduce the chance of ion suppression, leading to higher limitsof detection. The retention times and order of elution maychan
27、ge depending on the column used and need to be moni-tored.7.1.3 Tandem Mass Spectrometer SystemA MS/MS sys-tem capable of SRM analysis.6Any system that is capable ofperforming at the requirements in this procedure may be used.7.2 Filtration Device:7.2.1 Hypodermic SyringeA lock-tip glass syringe ca-
28、pable of holding a Millex HVSyringe Driven Filter Unit PVDF0.22 m,7,8or similar, may be used.7.2.1.1 A 25-mL lock-tip glass syringe size was used in thistest method.7.2.2 FilterMillex HV Syringe Driven Filter Unit PVDF0.22 m, or similar, may be used.8. Reagents and Materials8.1 Purity of ReagentsHig
29、h 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 theAmerican Chemical Society.9Other reagent gr
30、ades may be4AWatersAlliance High Performance Liquid Chromatography (HPLC) System,a trademark of the Waters Corporation, Milford, MA, was used to develop this testmethod. All parameters in this test method are based on this system and may varydepending on your instrument.5The Waters XBridge is a trad
31、emark of the Waters Corporation, Milford, MA.6A Waters Quattro micro API tandem quadrupole mass spectrometer, a trade-mark of the Waters Corporation, Milford, MA, was used to develop this test method.All parameters in this test method are based on this system and may vary dependingon your instrument
32、.7The sole source of supply of the Millex HV Syringe Driven Filter Unit PVDF0.45 m known to the committee at this time is Millipore Corporation, Catalog #SLHV033NS. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your comments will receiv
33、ecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.8Millex is a trademark of Merck KGAA, Darmstadt, Germany.9Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents
34、notlisted by the American Chemical Society, see Analar Standards 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 (DVL) and Reporting RangeAn
35、alyteDVL(g/L)Reporting Range(g/L)DPGBE 0.2 110EGBE 25 1251250D7731 172FIG. 1 Detection Verification Level Signal/Noise RatioFIG. 2 Reporting Level (Calibration Standard) Signal/Noise RatioD7731 173used provided they are first determined to be of sufficientlyhigh purity to permit their use without af
36、fecting the accuracy ofthe measurements.8.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type 1 of Specification D1193. It must be demonstrated thatthis water does not contain contaminants at concentrationssufficient to interfer
37、e with the analysis.8.3 GasesUltrapure nitrogen and argon.8.4 Acetonitrile (CAS # 75-05-8).8.5 Methanol (CAS # 67-56-1).8.6 Formic Acid (CAS # 64-18-6).8.7 2Propanol (CAS # 67-63-0).8.8 DPGBEDipropylene Glycol Monobutyl Ether (CAS #29911-28-2).8.9 EGBEEthylene Glycol Monobutyl Ether (CAS # 111-76-2)
38、.8.10 n-NP2EOnormal-Nonylphenol Diethoxylate (CAS #Not available).8.11 EGBE-D4(2-butoxyethanol (1,1,2,2-D4) (OptionalSurrogate, Unlabeled CAS # 111-76-2).9. Hazards9.1 Normal laboratory safety applies to this test method.Analysts should wear safety glasses, gloves, and lab coatswhen working in the l
39、ab. Analysts should review the MaterialSafety Data Sheets (MSDS) for all reagents used in this testmethod.10. Sampling10.1 Sampling and PreservationGrab samples should becollected in 20-mL pre-cleaned glass vials with TFE-fluorocarbonlined septa caps demonstrated to be free ofinterferences. The vial
40、 should be filled to approximately 20mL. This may be just below the neck of the vial, depending onthe vial manufacturer. This test method is based on a 20-mLsample size per analysis. Each sample should be collected induplicate and a quadruplicate sample must be included witheach sample batch of 10 f
41、or MS/MSD quality control analyses.Store samples between 0C and 6C from sample collection tosample preparation. Analyze the sample within five days ofcollection.11. Preparation of Apparatus11.1 Liquid Chromatograph Operating Conditions:411.1.1 Injection volumes of all calibration standards andsample
42、s are made at 100-L volume. The first sample analyzedafter the calibration curve is a blank to ensure there is nocarry-over. The gradient conditions for the liquid chromato-graph are shown in Table 2. Divert the column flow away fromthe electrospray source from 0 to 5 minutes after injection.Flow di
43、version to waste may be done using the mass spec-trometer divert valve. Divert tubing configurations vary frommanual injection. Sea water samples contain nonvolatile salts,the first 5 minute elution is diverted in order to keep the massspectrometer source clean.11.2 LC Conditions:11.2.1 Needle Wash
44、Solvent60 % Acetonitrile/40 %2-propanol.11.2.2 TemperaturesColumn, 30C; sample compartment,15C.11.2.3 Seal Wash60 % Acetonitrile/40 % 2-propanol.11.3 Mass Spectrometer Parameters:611.3.1 To acquire the maximum number of data points perSRM channel while maintaining adequate sensitivity, the tuneparam
45、eters may be optimized according to your instrument.Each peak requires at least 10 scans per peak for adequatequantitation. This procedure contains DPGBE, EGBE, and onesurrogate which are in three SRM acquisition functions tooptimize sensitivity. Variable parameters regarding retentiontimes, SRM tra
46、nsitions, and cone and collision energies areshown in Table 3. Mass spectrometer parameters used in thedevelopment of this test method are listed here:Capillary Voltage: 3.5 kVCone: Variable depending on analyte (Table 3)Extractor: 2 VoltsRF Lens: 0.2 VoltsSource Temperature: 120CDesolvation Tempera
47、ture: 350CDesolvation Gas Flow: 800 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 3)Exit Energy: 1Low Mass Resolution 2: 14.5High Mass resolution 2: 14.5Ion Energy 2: 0.8Multi
48、plier: 650Gas Cell Pirani Gauge: 7.0 10-3TorrInter-Channel Delay: 0.1 secondsInter-Scan Delay: 0.1 secondsDwell: 0.1 secondsSolvent Delay: 5 minutesTABLE 2 Gradient Conditions for Liquid ChromatographyTime (min) Flow (mL/min)Percent 95 % Water/ 5 %CH3CNPercent CH3CNPercent 2 % Formic Acid 95 %Water/
49、 5 % CH3CN0.0 0.30 95 0 52.0 0.30 95 0 55.0 0.30 0 95 514.0 0.30 0 95 515.0 0.30 95 0 518.0 0.30 95 0 5D7731 17412. Calibration and Standardization12.1 The mass spectrometer must be calibrated in accor-dance with manufacturer specifications before analysis. Inorder to obtain accurate analytical values through using thistest method within the confidence limits, the following proce-dures must be followed when performing this test method.Prepare all solutions in the lab using Class A volumetricglassware.12.2 Calibration and Sta
