ASTM_D_6196_-_03_2009.pdf

Designation:D619603(Reapproved 2009)Standard Practice forSelection of Sorbents,Sampling,and Thermal DesorptionAnalysis Procedures for Volatile Organic Compounds in Air1This standard is issued under the fixed designation D6196;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 practice is intended to assist in the selection ofsorbents and procedures for the sampling and analysis ofambient(1)2,indoor(2)and workplace(3,4)atmospheres fora variety of common volatile organic compounds(VOCs).Itmay also be used for measuring emissions from materials insmall or full scale environmental chambers or for humanexposure assessment.1.2 A complete listing of VOCs for which this practice hasbeen tested,at least over part of the measurement range(1.6),is shown in Tables 1-9.For other compounds this practice shallbe tested according to EN 1076(pumped);Practice D6246,ISO 16107,ANSI/ISEA 104,EN 838orEN 13528-1 EN 13528-2(diffusive);or other appropriate validation pro-tocols(Sections 13 and 14).(5,1)1.3 This practice is based on the sorption of VOCs from aironto selected sorbents or combinations of sorbents.Sampledair is either drawn through a tube containing one or a series ofsorbents(pumped sampling)or allowed to diffuse,undercontrolled conditions,onto the sorbent tube or tubes(diffusiveor passive sampling).The sorbed VOCs are subsequentlyrecovered by thermal desorption and analyzed by capillary gaschromatography.1.4 This practice applies to three basic types of samplersthat are compatible with thermal desorption:(1)pumpedsorbent tubes containing one or more sorbents;(2)axialdiffusive samplers(typically of the same physical dimensionsas standard pumped sorbent tubes and containing only onesorbent);and(3)radial diffusive samplers.1.5 This practice recommends a number of sorbents that canbe packed in sorbent tubes,for use in the sampling of a widerange of different volatile organic compounds boiling in therange 0 to 400C(v.p.15 to 0.01 kPa at 25C).1.5.1 For pumped sampling,sorbent selection is based onbreakthrough capacity.Single-bed tubes containing for ex-ample sorbent Type A3,4are appropriate for normal alkanesfrom n-C6(hexane)to n-C10(decane)and substances withsimilar volatility(v.p.15 to 0.3 kPa at 25C).More volatilematerials should be sampled on stronger sorbents,such assorbent Type B3,5.Other sorbent types than those specified maybe used,if their breakthrough capacities are adequate and theirthermal desorption blanks are sufficiently small.Examples aregiven in Appendix X2.A broader range of VOCs may besampled using multi-bed tubes.1.5.2 Guidance given for the selection of sorbents forpumped monitoring tubes can be applied equally well to axialdiffusive sampling tubes.The restriction to a single samplingsurface(hence single sorbent),limits the target analyte rangethat can be monitored by a single tube.However,the unobtru-sive nature and low cost of diffusive samplers usually meansthat two or more samplers containing different sorbents can beused in parallel without impacting study objectives.1.5.3 The high sampling rate and associated risk of backdiffusion associated with radial diffusive samplers typicallyrestricts the use of these samplers to compounds of equal orlower volatility than benzene.It also means that strongersorbents are generally required for these samplers whencompared with either axial diffusive or pumped sorbent tubes.1.6 This practice can be used for the measurement ofairborne vapors of these volatile organic compounds over awide concentration range.1.6.1 With pumped sampling,this practice can be used forthe measurement of airborne vapors of VOCs in a concentra-tion range of approximately 0.1 g/m3to 1 g/m3,for individualorganic compounds in 110 L air samples.The method is alsosuitable for the measurement of the airborne concentrations ofindividual components of volatile organic mixtures,provided1This practice is under the jurisdiction ofASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.05 on Indoor Air.Current edition approved March 1,2009.Published March 2009.Originallyapproved in 1997.Last previous edition approved in 2003 as D6196-03.DOI:10.1520/D6196-03R09.2The bold face numbers in parentheses refer to the list of references at the endof this practice.3If you are aware of alternative sorbent types,please provide this information toASTM Headquarters.Your comments will be carefully considered at a meeting ofthe responsible technical committee,which you may attend.4An example of sorbent Type A known to perform as specified in this practiceis Chromosorb 106 manufactured by Manville Corp.,USA and available fromseveral commercial sources.5An example of sorbent Type B known to perform as specified in this practiceis Car