1、Designation: D7731 11Standard 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 procedure covers the
3、 determination of DipropyleneGlycol Monobutyl Ether (DPGBE) and Ethylene GlycolMonobutyl Ether (EGBE) in sea water by direct injection usingliquid chromatography (LC) and detection with tandem massspectrometry (MS/MS). This analyte is qualitatively and quan-titatively determined by this method. This
4、 method adheres toselected reaction monitoring (SRM) mass spectrometry.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 signal/noise rati
5、o greater than 3:1. Fig. 1 and Fig. 2 display thesignal/noise ratio 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 preparation dilu-tion fact
6、or.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 to establish a
7、ppro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on Water2.
8、2 Other Standards:3EPApublication SW-846 Test Methods for Evaluating SolidWaste, Physical/Chemical Methods3. Terminology3.1 Definitions:3.1.1 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).3.1.2
9、reporting limit, RL, nthe concentration of thelowest-level calibration standard used for quantification.3.1.2.1 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
10、, the lowest calibration level of 100 ppb forEGBE would allow for a reporting limit of 125 ppb to beachieved.3.2 Abbreviations:3.2.1 ppbparts per billion, g/L3.2.2 pptparts per trillion, ng/L3.2.3 mMmillimolar,1x10-3moles/L3.2.4 NAno addition3.2.5 NDnon-detect1This test method is under the jurisdict
11、ion of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis forOrganic Substances in Water.Current edition approved May 1, 2011. Published May, 2011. DOI: 10.1520/D773111.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcont
12、act 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 from National Technical Information Service (NTIS), U.S.Department of Commerce, 5285 Port Royal Road, Springfield, VA, 22
13、161 or athttp:/www.epa.gov/epawaste/hazard/testmethods/index.htmTABLE 1 Detection Verification Level and Reporting RangeAnalyte DVL (g/L) Reporting Range (g/L)DPGBE 0.2 110EGBE 25 12512501Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United State
14、s.FIG. 1 Detection Verification Level Signal/Noise Ratio.FIG. 2 Reporting Level (Calibra tion standard) Signal/Noise Ratio.D7731 1124. 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 a re shipp
15、ed tothe lab 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) 302B Test lists96% biodegradation
16、 in 28 days.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 sett
17、leresulting 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 retentiontime and one SRM transition. The ta
18、rget analytes and surrogateare quantitated using the SRM transitions utilizing an externalcalibration. The final report issued for each sample lists theconcentration of DPGBE, EGBE and the surrogate recovery.5. Significance and Use5.1 DPGBE and EGBE have a variety of residential andindustrial applic
19、ations such 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 method has been investigated for use with reagentand sea water.6. Interferences6.1 Method interferences may be caused b
20、y contaminants 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 wat
21、er with 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 solvent
22、s should 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 System7
23、.1.1 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- XBridgey, 2.1 x 150mm, 3
24、.5 m particle size was used to develop this test method.Any column that achieves baseline resolution of these analytesmay be used. Baseline resolution simplifies data analysis andcan reduce the chance of ion suppression, leading to higherlimits of detection. The retention times and order of elutionm
25、ay change depending on the column used and need to bemonitored.7.1.3 Tandem Mass Spectrometer SystemA MS/MS sys-tem capable of SRM analysis.5Any 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 Syring
26、e ca-pable of holding a Millext HV Syringe Driven Filter UnitPVDF 0.22 m or similar may be used.7.2.1.1 A 25 mL Lock Tip Glass Syringe size was used inthis test method.7.2.2 FilterMillext HV Syringe Driven Filter Unit PVDF0.22 m (Millipore Corporation, Catalog #SLGV033NS) orsimilar may be used.8. Re
27、agents 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 t
28、heAmerican Chemical Society.6Other reagent grades may beused provided they are first determined to be of sufficientlyhigh purity to permit their use without affecting the accuracy ofthe measurements.8.2 Purity of WaterUnless otherwise indi cated, refer-ences to water shall be understood to mean reag
29、ent waterconforming to ASTM Type 1 of Specification D1193. It mustbe demonstrated that this water does not contain contaminantsat concentrations sufficient to interfere 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 Ac
30、id (CAS # 64-18-6).8.7 Propanol (CAS # 67-63-0).8.8 DPGBEDipropylene Glycol Monobutyl Ether (CAS #29911-28-2).4A Waters Alliance High Performance Liquid Chromatography (HPLC) Systemwas used to develop this test method. All parameters in this test method are basedon this system and may vary depending
31、 on your instrument.5AWaters Quattro microAPI tandem quadrupole mass spectrometer was used todevelop this test method.All parameters in this test method are based on this systemand may vary depending on your instrument.6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical So
32、ciety, Washington, D.C. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia andNational Formulators, U.S. Pharmacopeial Convention, Inc. (USPC), Rockvill
33、e,MD.D7731 1138.9 EGBEEthylene Glycol Monobutyl Ether (CAS# 111-76-2).8.10 n-NP2EOnormal- Nonylphenol Diethoxylate (CAS#Not available).78.11 EGBE-D4 (2-butoxyethanol (1,1,2,2-D4) (OptionalSurrogate, Unlabeled CAS# 111-76- 2).89. Hazards9.1 Normal laboratory safety applies to this method. Ana-lysts s
34、hould wear safety glasses, gloves, and lab coats whenworking in the lab. Analysts should review the Material SafetyData Sheets (MSDS) for all reagents used in this method.10. Sampling10.1 Sampling and PreservationGrab samples should becollected in 20 mL pre-cleaned glass vials with Teflont linedsept
35、a caps demonstrated to be free of interferences. The vialshould be filled to approximately 20 mL. This may be justbelow the neck of the vial, depending on the vial manufacturer.This test method is based on a 20 mL sample size per analysis.Each sample should be collected in duplicate and a quadrupli-
36、cate sample must be included with each sample batch of 10 forMS/MSD quality control analyses. Store samples between 0Cand 6C from sample collection to sample preparation.Analyzethe sample within 5 days of collection.11. Preparation of Apparatus11.1 Liquid Chromatograph Operating Conditions411.1.1 In
37、jection volumes of all calibration standards andsamples 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 electrosp
38、ray source for 0 to 5 minutes after injection. Flowdiversion to waste may be done using the mass spectrometerdivert valve, divert tubing configurations vary from manualinjection. Sea water samples contain nonvolatile salts, the first5 minute elution is diverted in order to keep the massspectrometer
39、source clean.11.2 LC Conditions:11.2.1 Needle Wash Solvent60% Acetonitrile/40%2-propanol11.2.2 TemperaturesColumn, 30C; Sample compart-ment, 15C.11.2.3 Seal Wash60% Acetonitrile/40% 2-propanol.11.3 Mass Spectrometer Parameters5:11.3.1 To acquire the maximum number of data points perSRM channel while
40、 maintaining adequate sensitivity, the tuneparameters 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. Variab
41、le parameters regarding retentiontimes, SRM transitions, and cone and collision energies areshown in Table 3. Mass spectrometer parameters used in thedevelopment of this method are listed here:Capillary Voltage: 3.5 kVCone: Variable depending on analyte (Table 3)Extractor: 2 VoltsRF Lens: 0.2 VoltsS
42、ource Temperature: 120CDesolvation Temperature: 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 Ma
43、ss resolution 2: 14.5Ion Energy 2: 0.8Multiplier: 650Gas Cell Pirani Gauge: 7.0 x 10-3TorrInter-Channel Delay : 0.1 secondsInter-Scan Delay: 0.1 secondsDwell: 0.1 secondsSolvent Delay: 5 minutes12. Calibration and Standardization12.1 The mass spectrometer must be calibrated p er manu-facturer specif
44、ications before analysis. In order to obtainaccurate analytical values through using this test method withinthe confidence limits, the following procedures must be fol-lowed when performing the test method. Prepare all solutionsin the lab using Class A volumetric glassware.12.2 Calibration and Stand
45、ardizationTo calibrate the in-strument, analyze six calibration standards and the DVLcontaining (nominal concentrations in Table 4) DPGBE, EGBEand n-NP2EO.Acalibration solution is prepared from standardmaterials or they are purchased as certified solutions. Level 6calibration solution containing the
46、 targets and surrogate isprepared and aliquots of that solution are diluted to prepare7Asource of n-NP2EO isAccustandard, Inc. 125 Market Street, New Haven, CT06513 or Cambridge Isotope Laboratories, 50 Frontage Road, Andover, MA01810-5413.8A source of EGBE-D4 is Cambridge Isotope Laboratories, 50 F
47、rontage Road,Andover, MA 01810-5413.TABLE 2 Gradient C onditions for Liquid ChromatographyTime (min) Flow (mL/min) Percent 95% Water/ 5% CH3CN Percent CH3CN Percent 2% Formic Acid 95% Water/ 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 11
48、4Levels 1 through 5 and the DVL. The following steps willproduce standards with the concentration values shown inTable 4. The analyst is responsible for recording initialcomponent weights correctly and calculating and preparingappropriate dilution calculations.12.2.1 Prepare Level 6 calibration stoc
49、k standard at 1000ppb for EGBE, 8 ppb for DPGBE and 40 ppb for n-NP2EO in80% water/20% acetonitrile. The EGBE and DPGBE concen-trated stock solutions were prepared in methanol at approxi-mately 2 g/L concentration and the n- NP2EO surrogateconcentrated stock solution was prepared in acetonitrile atapproximately 0.5 g/L. The preparation of the stock standardcan be accomplished using different volumes and concentra-tions of stock solutions as is accustomed in the individuallaboratory. Depending on the prepared stock concentrations,the so
