ASTM_D_2908_-_91_2011.pdf

Designation:D290891(Reapproved 2011)Standard Practice forMeasuring Volatile Organic Matter in Water by Aqueous-Injection Gas Chromatography1This standard is issued under the fixed designation D2908;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 covers general guidance applicable tocertain test methods for the qualitative and quantitative deter-mination of specific organic compounds,or classes of com-pounds,in water by direct aqueous injection gas chromatogra-phy(1,2,3,4).21.2 Volatile organic compounds at aqueous concentrationsgreater than about 1 mg/L can generally be determined bydirect aqueous injection gas chromatography.1.3 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 ASTM Standards:3D1129 Terminology Relating to WaterD1192 Guide for Equipment for Sampling Water and Steamin Closed Conduits(Withdrawn 2003)4D1193 Specification for Reagent WaterD3370 Practices for Sampling Water from Closed ConduitsE260 Practice for Packed Column Gas ChromatographyE355 Practice for Gas Chromatography Terms and Relation-ships3.Terminology3.1 Definitions:3.1.1 The following terms in this practice are defined inaccordance with Terminology D1129.3.1.2“ghosting”or memory peaksan interference,show-ing as a peak,which appears at the same elution time as theorganic component of previous analysis.3.1.3 internal standarda material present in or added tosamples in known amount to serve as a reference measurement.3.1.4 noisean extraneous electronic signal which affectsbaseline stability.3.1.5 relative retention ratiothe retention time of theunknown component divided by the retention time of theinternal standard.3.1.6 retention timethe time that elapses from the intro-duction of the sample until the peak maximum is reached.3.2 For definitions of other chromatographic terms used inthis practice,refer to Practice E355.4.Summary of Practice4.1 This practice defines the applicability of various col-umns and conditions for the separation of naturally occurringor synthetic organics or both,in an aqueous medium forsubsequent detection with a flame ionization detector.Aftervaporization,the aqueous sample is carried through the columnby an inert carrier gas.The sample components are partitionedbetween the carrier gas and a stationary liquid phase on an inertsolid support.The column effluent is burned in an air-hydrogenflame.The ions released from combustion of the organiccomponents induce an increase in standing current which ismeasured.Although this method is written for hydrogen flamedetection,the basic technology is applicable to other detectorsif water does not interfere.4.2 The elution times are characteristic of the variousorganic components present in the sample,while the peak areasare proportional to the quantities of the components.A discus-sion of gas chromatography is presented in Practice E260.5.Significance and Use5.1 This practice is useful in identifying the major organicconstituents in wastewater for support of effective in-plant orpollution control programs.Currently,the most practical meansfor tentatively identifying and measuring a range of volatile1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.06 on Methods for Analysis forOrganic Substances in Water.Current edition approved May 1,2011.Published June 2011.Originallyapproved in 1970.Last previous edition approved in 2005 as D2908 91(2005).DOI:10.1520/D2908-91R11.2The boldface numbers in parentheses refer to the list of references at the end ofthis practice.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 organic compounds is gas-liquid chromatography.Positiveidentification requires supplemental testing(for example,mul-tiple columns,speciality detectors,spectroscopy,or a combi-nation of these techniques).6.Interferences6.1 Particulate MatterParticulate or suspended mattershould be removed by centrifugation or membrane filtration ifcomponents of interest are not altered.This pretreatment willprevent both plugging of syringes and formation of condensa-tion nuclei.Acidification will often facilitate the dissolvi