1、Designation: D7892 15Standard Test Method forDetermination of Total Organic Halides, Total Non-MethaneHydrocarbons, and Formaldehyde in Hydrogen Fuel by GasChromatography/Mass Spectrometry1This standard is issued under the fixed designation D7892; the number immediately following the designation ind
2、icates 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 The gas chromatography/mass spectrometry
3、(GC/MS)procedure described in this method is used to determineconcentrations of total organic halides and total non-methanehydrocarbons (TNMHC) by measurement of individual targethalocarbons (Table 1) and hydrocarbons (includingformaldehyde, Table 1 and Table 2), respectively. Measure-ment of these
4、substances is required for application of SAEJ2719 to hydrogen fuel quality where this fuel is intended foruse in fuel cell vehicles. SAE 2719 states hydrogen fuel isexpected to contain less than 0.05 mole/mole total haloge-nates (including organic halides), 2 mole/mole total non-methane hydrocarbon
5、s (C1 Basis, 3.2.16) and 0.01 mole/moleformaldehyde.1.2 Based upon the GC/MS/full scan analysis of a 400 mLhydrogen sample, the reporting limit (RL) is 0.001 mole/molefor each target compound listed in Table 1 and Table 2, with theexception of 0.002 mole/mole for ethane and 0.002 mole/mole for ethen
6、e.1.3 Mention of trade names in this standard does notconstitute endorsement or recommendation for use. Othermanufacturers equipment or equipment models can be used.1.4 The values stated in SI units are to be regarded asstandard.1.5 This standard does not purport to address all of thesafety concerns
7、, 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 to use.2. Referenced Documents2.1 ASTM Standards:2D4150 Terminology Relating to Gaseous Fuels
8、D7606 Practice for Sampling of High Pressure Hydrogenand Related Fuel Cell Feed Gases2.2 Other Standards:3SAE J2719 Information Report on the Development of aHydrogen Quality Guideline for Fuel Cell Vehicles3. Terminology3.1 DefinitionsFor definitions of terms use in this testmethod, refer to Termin
9、ology D4150.3.2 Definitions:3.2.1 absolute pressurepressure measured with referenceto absolute zero pressure usually expressed as kPa, mm Hg, baror psi.3.2.2 constituentcomponent (or compound) found withina hydrogen fuel mixture.3.2.3 contaminantcontaminant as defined in this applica-tion is an impu
10、rity that adversely affects the components withina fuel cell system or hydrogen storage system.3.2.4 cryogena refrigerant is used to obtain very lowtemperatures. The cryogen used in this method is liquidnitrogen (bp -196 C).3.2.5 dynamic calibrationCalibration of an analytical sys-tem uses gaseous c
11、alibration standard generated by diluting aknown concentration of compressed gaseous standard with adiluent gas.3.2.6 fuel cell grade hydrogenhydrogen satisfying thespecifications in SAE J2719.1This test method is under the jurisdiction ofASTM Committee D03 on GaseousFuels and is the direct responsi
12、bility of Subcommittee D03.14 on Hydrogen andFuel Cells.Current edition approved June 1, 2015. Published July 2015. DOI: 10.1520/D7892-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
13、information, refer to the standards Document Summary page onthe ASTM website.3Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096, http:/www.sae.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1TABLE 1
14、 Organic HalidesTarget Compounds Formulas MW BPC MPC CAS No. Retention Time(min)1,1,1-Trichloroethane C2H3Cl3133.4 74 -33 71-55-6 8.8761,1,2,2-Tetrachloroethane C2H2Cl4167.9 147 -44 79-34-5 14.6271,1,2-Trichloroethane C2H3Cl3133.4 114 -37 79-00-5 11.6071,2-Dibromoethane C2H4Br2187.9 132 10 106-93-4
15、12.5551,1-Dichloroethane C2H4Cl299 57 -97 75-34-3 7.0341,1-Dichloroethene C2H2Cl296.9 32 -122 75-35-4 5.9271,2,4-Trichlorobenzene C6H3Cl3181.5 214 17 120-82-1 19.7951,2,3,4-tetrachlorohexafluorobutane C4Cl4F6303.4 134 0 dl; 73 meso 375-45-1 13.0081,2-Dichloroethane C2H4Cl299 84 -35 107-06-2 8.6581,2
16、-Dichloropropane C3H6Cl2113 96 -100 78-87-5 10.0061,2-Dichlorobenzene C6H4Cl2147 181 -17 95-50-1 17.3341,3-Dichlorobenzene C6H4Cl2147 173 -24 541-73-1 16.7991,4-Dichlorobenzene C6H4Cl2147 174 54 106-46-7 16.881Benzyl Chloride C7H7Cl 126.6 179 -39 100-44-7 16.769Bromodichloromethane CHBrCl2162 90 -57
17、 75-27-4 10.189Bromoform CHBr3252.7 149 8 75-25-2 14.303Bromomethane CH3Br 94.9 4 -94 74-83-9 4.326Carbon tetrachloride CCl4153.8 77 -23 56-23-5 9.418Chlorobenzene C6H5Cl 112.6 131 -45 108-90-7 13.626Chloroethane C2H5Cl 64.5 12 -139 75-00-3 4.52Chloroform CHCl3119.4 61 -64 67-66-3 7.987Chloromethane
18、 CH3Cl 50.5 5 -24 74-87-3 3.504cis-1,2-dichloroethene C2H2Cl297 60 -81 156-59-2 7.728cis-1,3-Dichloropropene C3H4Cl2111 104 -85 10061-01-5 10.948Dibromochloromethane CHBr2Cl 208.3 119 -22 124-48-1 12.308Dichlorodifluoromethane CCl2F2120.9 -30 -158 75-71-8 3.251Freon113 (1,1,2-Trichloro-1,2,2-trifluo
19、roethane) C2Cl3F3187.4 48 -35 76-13-1 6.239Freon114 (1,2-Dichlorotetrafluoroethane) C2Cl2F4170.9 4 -94 76-14-2 3.641Hexachlorobutadiene C4Cl6260.8 210220 -22 to -19 87-68-3 20.56Methylene chloride CH2Cl284.9 40 -97 75-09-2 6.015Tetrachloroethene C2Cl4165.8 121 -19 127-18-4 12.943trans-1,2-dichloroet
20、hene C2H2Cl297 48 -81 156-60-5 6.839trans-1,3-Dichloropropene C3H4Cl2110 112 -85 10061-02-6 11.401Trichloroethene C2HCl3131.4 87 -73 79-01-6 10.177Trichlorofluoromethane CCl3F 137.4 23 -111 75-69-4 5.321Vinyl Chloride C2H2Cl262.5 -13 -154 75-01-4 3.8TABLE 2 Non-Halogenated Non-Methane HydrocarbonsTa
21、rget Compounds Formula MW BPC MPC CAS No. Retention Time(min)1,2,4-Trimethylbenzene C9H12120.20 169 -44 95-63-6 16.5571,3,5-Trimethylbenzene C9H12120.20 165 -45 108-67-8 16.0451,3-Butadiene C4H654.09 -4 -109 106-99-0 3.9851,4-Dioxane C4H8O288.11 101 12 123-91-1 10.6012-Butanone C4H8O 72.11 80 -86 78
22、-93-3 7.5162-Hexanone C6H12O 100.16 128 -56 591-78-6 12.3254-Ethyltoluene C9H12120.19 162 -62 622-96-8 15.9694-Methyl-2-Pentanone C6H12O 100.16 117118 -85 108-10-1 11.154Acetone C3H6O 58.08 5657 -95 to -93 67-64-1 5.356Ethene C2H428.05 -104 -169 9002-88-4 2.771Benzene C6H678.11 80 6 71-43-2 9.294Cyc
23、lohexane C6H1284.16 81 6 110-82-7 9.529Ethane C2H630.07 -89 -183 74-84-0 2.82Ethanol C2H6O 46.07 78 -114 64-17-5 5.556Ethyl Acetate C4H8O288.11 77 -84 141-78-6 7.958Ethylbenzene C8H10106.17 136 -95 100-41-4 13.962Formaldehyde CH2O 30.03 -19 -92 50-00-0 3.025Heptane C7H16100.2 9899 -91 to -90 142-82-
24、5 10.342Hexane C6H1486.18 6869 -96 to -94 110-54-3 7.875Isopropyl Alcohol C3H8O 60.1 83 -89 67-63-0 6.38Methyl tert-Butyl Ether C5H12O 88.15 55 -109 1634-04-4 7.199Propane C3H844.1 -42 -188 74-98-6 3.173Propene C3H642.08 -48 -185 115-07-1 3.137Styrene C8H8104.16 145 -31 100-42-5 14.503Tetrahydrofura
25、n C4H8O 72.11 66 -108 109-99-9 8.529Toluene C7H892.15 111 -95 108-88-3 11.866Vinyl acetate C4H6O286.09 73 -93 108-05-4 7.134Xylenes, m however, otherUHP gases, such as helium, can also be used providedapplication requirements are met. No target compounds inTable 1 and Table 2 are present at greater
26、than reporting limits(see 1.2) in the carrier gas.7.3 Sample Transferring Gas for Sample ConcentrationUHP hydrogen is used; however, other UHP gases, such ashelium, can also be used provided application requirements aremet. See 10.3.7.4 Liquid NitrogenRequired for cryogenic cooling.8. Equipment Prep
27、aration8.1 GC/MS and Sample Concentration SystemPlaced intoservice in accordance to the manufacturers instructions withperformance of daily GC/MS mass calibration using perfluo-rotributylamine (FC-43).8.2 Liquid Nitrogen DewarA 160 to 230 L liquid nitrogenDewar with a head pressure of 0.15 MPa (22 p
28、si) is used forcryogenic cooling.9. Hazards9.1 WarningMercury has been designated by many regu-latory agencies as a hazardous material that can cause seriousmedical issues. Mercury, or its vapor, has been demonstrated tobe hazardous to health and corrosive to materials. Cautionshould be taken when h
29、andling mercury and mercury contain-ing products. See the applicable product Safety Data Sheet(SDS) for additional information. Users should be aware thatselling mercury and/or mercury containing products into yourstate or country may be prohibited by law.10. Laboratory Procedures10.1 Sampling Proce
30、duresSee Practice D7606.10.2 Sample ReceiptExamine the overall condition ofeach sample container; perform leak checks and record obser-vations in a dedicated logbook. Each container should possessan attached sample identification tag that includes the weight ofhydrogen sampled, pressure of hydrogen
31、in the container, thesampling place, date and time of sample collection.10.3 Sample Concentration and AnalysisThe four steps ofsample concentration are described below.10.3.1 Concentration Using a Glass Bead TrapFlow20 mL of the standard containing 100 ppb(v) of each internalstandard (3.2.9) and sur
32、rogate (3.2.15) at a flow rate of100 mL min through a glass bead trap cooled to -150 C.Then, pass 400 mL of a hydrogen sample (10.3.1.1) or knownvolume of gaseous calibration standards, at the same flow rate,through the glass bead trap at -150 C. The flow rate andsample volume passing through the tr
33、ap is established using anelectronic flow controller at the flow outlet end of the trap. Thisprocess will trap all the target compounds, internal standards,surrogates, and trace water contained in the hydrogen sampleor in gaseous calibration standards. However, if the hydrogensample contains the non
34、-hydrogen constituents with theirconcentrations higher than the highest concentration of theinitial calibration (10.4), less volume of the hydrogen samplesshould be used such that the highest compound concentrationis within initial calibration range (10.4). In this case, thereporting limits will be
35、adjusted by multiplying the reportinglimits by a dilution factor, which is 400 mL over the hydrogenvolume (mL) analyzed.10.3.1.1 Method to Flow Hydrogen Sample from HydrogenFuel Sample ContainerThe hydrogen samples after samplingin accordance with Practice D7606 are generally around6.9 MPa (1000 psi
36、). To take a 400 to 500 mL high pressurehydrogen sample directly, as described in 10.3.1, may bechallenging. One method to reduce the hydrogen pressurebefore sample concentration to a more easily handled value isto attach a short electropolished stainless steel (SS) tubing tothe sample container val
37、ve. The other end of the short SStubing is connected through an inlet valve to the inlet line ofthe sample concentration system, as shown in Fig. 1. The shortSS tubing must be evacuated using a vacuum pump beforeD7892 154sample concentration. The hydrogen sample introduction pro-cess is accomplished
38、 by pressurizing the short SS tubing whilethe inlet valve is closed. Then, upon closing the samplecontainer valve, the inlet valve is opened, thus expanding thehigh pressure hydrogen into the sample concentration systemthrough the inlet line; thereby, achieving a lower sampleintroduction pressure. T
39、he process is repeated several timesuntil enough volume of sample taken using an electronic flowcontroller (10.3.1), which is not only controlling and measur-ing the sample flow, but also integrating the total flow so thatthe volume of the sample can be measured in real time.10.3.2 Desorption of the
40、 Target Compounds from the GlassBead Trap to the Tenax TrapDesorb the target compounds onthe glass bead trap at a temperature of 10 C onto a Tenax trapwhich is maintained at -60 C with an UHP hydrogen flow at10 mL/min. This process leaves water in the glass bead trapand dehydrates the samples or sta
41、ndards. The dehydration ofthe samples or standards is important for the analysis offormaldehyde since formaldehyde may not be detected by thismethod without this dehydration step. The reason is probablydue to that formaldehyde is in equilibrium with methanediol,which is more predominating in the pre
42、sent of water. Thisdehydration step is capable of removing the excess water fromthe hydrogen samples containing moisture so that formalde-hyde at low concentration in these hydrogen samples can bedetected.10.3.3 Cryo-focusingThe organic compounds containedon the Tenax trap are desorbed at 180 C for
43、2 min andcyro-focused onto a 0.53 mm ID cryo-focusing column at-170 C.10.3.4 Desorption of Cryo-focusing ColumnThe targetcompounds on the cryo-focusing column are rapidly desorbedat 80 C and released into an analytical capillary column (see6.5).10.3.5 The GC/MS acquisition starts simultaneously upon
44、desorption of the cryo-focusing column. Within the initial4.5 min, the mass spectrometer scans from m/e 23 to 100 toprovide a determination of ethene, ethane, propene, propane,and formaldehyde. The scan is then changed to m/e 34-550 toidentify and quantify the remaining compounds listed in Table1 an
45、d Table 2.10.4 Initial CalibrationThe initial calibration is the se-quential analyses of three to five calibration standards atdifferent concentrations from the lowest concentration at thereporting limits to the highest concentration ten or twenty timesof the reporting limits. The acceptance criteri
46、a for initialcalibrations are listed below.10.4.1 All target compounds in the analysis of the standardat reporting limit must be detected at or above 3 timessignal-to-noise level.10.4.2 The relative standard deviation (%RSD) of the re-sponse factors (RF, 10.1) of each compound in the initialcalibrat
47、ion should be less than 30% to demonstrate the linearityof each compound over initial calibration concentration range.The method blank (10.7) and samples can be analyzed afterinitial calibration within 24 hours from the start of the firstinitial calibration analysis.10.5 Continuous CalibrationThe re
48、porting limit standardis firstly analyzed each day and all the target compounds mustbe detected at or above 3 times signal-to-noise level before thisanalysis can be employed as continuous calibration. An ex-ample of the GC/MS full scan chromatogram of all thecompounds in Table 1 and Table 2 at the r
49、eporting limits isshown in Fig. 2. Fig. 3 is the extracted ion chromatograms offormaldehyde at 1 ppb(v) by GC/MS in full scan. The methodblank (10.7) and samples can be analyzed afterwards within24 hours from the start of the continuous calibration. For targetcompounds found in samples above the reporting limits, thedifference of its average initial calibration RF from its dailycontinuous calibration RF are expected to be less than 30 %.10.6 Method Detection Limit DemonstrationRefer to4 CFR136, appendix B (2.2.6).10.7 Method Blank Anal
