ASTM_D_7649_-_10.pdf

Designation:D764910Standard Test Method forDetermination of Trace Carbon Dioxide,Argon,Nitrogen,Oxygen and Water in Hydrogen Fuel by Jet Pulse Injectionand Gas Chromatography/Mass Spectrometer Analysis1This standard is issued under the fixed designation D7649;the number immediately following 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 test method describes a procedure primarily for thedetermination of carbon dioxide,argon,nitrogen,oxygen andwater in high pressure fuel cell grade hydrogen by gaschromatograph/mass spectrometer(GC/MS)with injection ofsample at the same pressure as sample without pressurereduction,which is called“Jet Pulse Injection”.The proceduresdescribed in this method were designed to measure carbondioxide at 0.5micromole per mole(ppmv),Argon 1 ppmv,nitrogen 5 ppmv and oxygen 2 ppmv and water 4 ppmv.1.2 The values stated in SI units are standard.The valuesstated in inch-pound units are for information only.1.3 The mention of trade names in standard does notconstitute endorsement or recommendation for use.Othermanufacturers of equipment or equipment models can be used.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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 Other Standards:SAE TIR J2719 Information Report on the Development ofa Hydrogen Quality Guideline for Fuel Cell VehiclesApril200823.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 absolute pressurepressure measured with referenceto absolute zero pressure,usually expressed as kPa,mm Hg,bar or psi.All the pressures mentioned in this method areabsolute pressure.3.1.2 constituentA component(or compound)foundwithin a hydrogen fuel mixture.3.1.3 contaminantimpurity that adversely affects the com-ponents within the fuel cell system or the hydrogen storagesystem by reacting with its components.An adverse effect canbe reversible or irreversible.3.1.4 dynamic calibrationcalibration of an analytical sys-tem using calibration gas standard generated by diluting knownconcentration compressed gas standards with hydrogen,asused in this method for carbon dioxide,argon,nitrogen andoxygen(7.3 and 7.4).3.1.5 extracted ion chromatogram(EIC)a GC/MS chro-matogram where a selected ion is plotted to determine thecompound(s)of interest.3.1.6 fuel cell grade hydrogenhydrogen satisfying thespecifications in SAE TIR J2719.3.1.7 hydrogen fuelhydrogen to be tested without compo-sitional change due to sample introduction,etc.3.1.8 jet pulse injectionhigh pressure hydrogen fuelsample is introduced instantaneously at the same pressure intoGC/MS.3.1.9 relative humidityratio of actual pressure of existingwater vapor to maximum possible pressure of water vapor inthe atmosphere at the same temperature,expressed as apercentage.3.1.10 response factor(RF)-the amount in volume(L)ofan analyte divided by the EIC area of the analyte.3.1.11 static calibrationcalibration of an analytical sys-tem using standards in a matrix,state or manner different thanthe samples to be analyzed,as used in this method for waterconcentration in hydrogen.3.2 Acronyms:3.2.1 FCVfuel cell vehicle.3.2.2 PEMFCproton exchange membrane fuel cell.4.Summary of Test Method4.1The simultaneous analysis of carbon dioxide,argon,nitrogen,oxygen and water at 0.5 5 ppmv(micromole per1This test method is under the jurisdiction ofASTM Committee D03 on GaseousFuels and is the direct responsibility of Subcommittee D03.14 on Hydrogen andFuel Cells.Current edition approved Dec.1,2010.Published February 2011.DOI:10.1520/D764910.2Available from SAE International(SAE),400 Commonwealth Dr.,Warrendale,PA 15096-0001,http:/aerospace.sae.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 mole)in hydrogen fuel samples from fueling stations ischallenging due to high hydrogen fuel sample pressure andpossible contaminations from ambient air.4.2 In this method,a small stainless steel loop is initiallypressurized with high pressure hydrogen standard or samplewithout any pressure regulation or restriction(“Sample LoopPressurization”,Fig.1).The hydrogen in the loop is thenreleased entirely as a“jet pulse”into a T-union which splitssample into a 0.25 m ID 30 m long capillary column and anelectronic flow controller(EFC)used to vent excess hydrogento the atmosphere(“Jet Pulse Injection”,Fig.2).Less than 1%of hydrogen enters the capillary column with the remainingsample venting to atmosphere through EFC.As demonstratedin Appendix X1,the hydrogen volume“jet pulse injected”intothe capillary column is a constant volume and in