ASTM_D_5241_-_92_2011.pdf

Designation:D524192(Reapproved 2011)Standard Practice forMicro-Extraction of Water for Analysis of Volatile and Semi-Volatile Organic Compounds in Water1This standard is issued under the fixed designation D5241;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 standard procedures for extractionof volatile and semi-volatile organic compounds from waterusing small volumes of solvents.1.2 The compounds of interest must have a greater solubil-ity in the organic solvent than the water phase.1.3 Not all of the solvents that can be used in microextraction are addressed in this practice.The applicability of asolvent to extract the compound(s)of interest must be demon-strated before use.1.4 This practice provides sample extracts suitable for anytechnique amenable to solvent injection such as gas chroma-tography or high performance liquid chromatography(HPLC).1.5 The values stated in SI units are to be regarded as thestandard.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 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.For specific hazardstatements,see Section 9.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD3370 Practices for Sampling Water from Closed ConduitsD3694 Practices for Preparation of Sample Containers andfor Preservation of Organic ConstituentsD3856 Guide for Management Systems in LaboratoriesEngaged in Analysis of WaterD3973 Test Method for Low-Molecular Weight HalogenatedHydrocarbons in WaterD4210 Practice for Intralaboratory Quality Control Proce-dures and a Discussion on Reporting Low-Level Data(Withdrawn 2002)3D4448 Guide for Sampling Ground-Water Monitoring WellsD5175 Test Method for Organohalide Pesticides and Poly-chlorinated Biphenyls in Water by Microextraction andGas Chromatography3.Summary of Practice3.1 This practice employs liquid/liquid extraction to isolatecompounds of interest.The sample is added to an extractiondevice.The solvent may be added to the sample container or anextraction device and extracted for a period of 5 min.Thesolvent is then ready for analysis.If required,the pH may beadjusted and salt may be added prior to extraction to increasethe extraction specificity and efficiency.3.2 The solvent extract may be further processed usingsample clean-up and concentration techniques.The analytes inthe solvent may be analyzed using instrumental methods forspecific volatile or semivolatile organic compounds.Thispractice does not include sample extract clean-up methods.4.Significance and Use4.1 This practice provides a general procedure for thesolvent extraction of volatile and semi-volatile organic com-pounds from a water matrix.Solvent extraction is used as theinitial step in the solvent extraction of organic constituents forthe purpose of quantifying extractable organic compounds.4.2 Typical detection limits that can be achieved usingmicro-extraction techniques with gas chromatography(GC)with flame ionization detector(FID),electron capture detector(ECD),or with a mass spectrometer(GC/MS)range frommilligrams per litre(mg/L)to nanograms per litre(ng/L).The1This 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 1992.Last previous edition approved in 2004 as D5241 92(2004).DOI:10.1520/D5241-92R11.2For 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.3The 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 detection limit,linear concentration range,and sensitivity ofthe test method for a specific organic compound will dependupon the sample clean-up,injection volume,solvent to sampleratio,solvent concentration methods used,and the determina-tive technique employed.4.3 Micro-extraction has the advantage of speed,simpleextraction devices,and the use of small amounts of sample andsolvents.4.3.1 Selectivity can be improved by the choice of solvent(usually hexane or pentane)or mixed solvents,extraction timeand temperature,and ionic strength of t