ASTM_D_5954_-_98_2014e1.pdf

Designation:D595498(Reapproved 2014)1Standard Test Method forMercury Sampling and Measurement in Natural Gas byAtomic Absorption Spectroscopy1This standard is issued under the fixed designation D5954;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.1NOTEMercury caveat was added editorially to the Scope in April 2014.1.Scope1.1 This test covers the determination of total mercury innatural gas at concentrations down to 1 ng/m3.It includesseparate procedures for both sampling and atomic absorptionspectrophotometric determination of mercury.The proceduredetects both inorganic and organic forms of mercury.1.2 The values stated in SI units are to be regarded as thestandard.1.3 Warning:Mercury 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 handling 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.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 ASTM Standards:2D1193 Specification for Reagent Water3.Summary of Test Method3.1 Mercury in a gas stream is adsorbed onto gold-coatedsilica beads and subsequently directly desorbed by heat into along path-length quartz cell connected to an atomic absorptionspectrophotometer.Mercury atoms are detected by measuringtheir absorbance of light from a mercury source lamp at acharacteristic wavelength.The mercury concentration is ob-tained from the absorbance peak area by comparison tostandards prepared at the time of analysis.4.Significance and Use4.1 This test method can be used to measure the level ofmercury in natural gas streams for purposes such as determin-ing compliance with regulations,studying the effect of variousabatement procedures on mercury emissions,checking thevalidity of direct instrumental measurements,and verifyingthat mercury concentrations are below those required fornatural gas processing and operation.4.2 Adsorption of the mercury on gold-coated beads canremove interferences associated with the direct measurementof mercury in natural gas.It preconcentrates the mercurybefore analysis thereby offering measurement of ultra-lowaverage concentrations in a natural gas stream over a long spanof time.It avoids the cumbersome use of liquid spargers withon-site sampling,and eliminates contamination problems as-sociated with the use of potassium permanganate solutions.3,4,55.Apparatus5.1 Atomic Absorption Spectrophotometer,equipped with a10-cm-long path quartz absorption cell and a mercury sourcelamp(EDL or other high intensity lamp).It must be capable ofcollecting and integrating data over a 30-to 60-s time window.Background capabilities are strongly recommended.NOTE1Detection sensitivity may vary significantly depending on thetype of spectrophotometer and its accessories.1This test method is under the jurisdiction ofASTM Committee D03 on GaseousFuels and is the direct responsibility of Subcommittee D03.05 on Determination ofSpecial Constituents of Gaseous Fuels.Current edition approved Dec.1,2006.Published April 2014.Originallyapproved in 1996.Last previous edition approved 2006 as D595498(2006).DOI:10.1520/D5954-98R14.2For 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.3Schroeder,W.H.,“Sampling andAnalysis of Mercury and its Compounds in theAtmosphere,”Environmental Science&Technology,16,1982,394A399A.4Chao,S.S.,and Attari,A.,“Characterization and Measurements of Natural GasTrace ConstituentsVolume II:Survey,”Final Report GRI-94/0243.2,June 1994.5Braman,R.S.,and Johnson,D.L.,“Selective Absorption Tubes and EmissionTechnique for the Determination of Ambient Forms of Mercury in Air,”Environ-mental Science&Technology,8,1974,pp.9961003.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 Rotameter or Other Flow Measurement Device capableof attaining and regulating air at approximately 500 mL/min.5.3 Rotameter or Other Flow Measurement Device capableof attaining and regulating the natural gas sample at approxi-mately 1000 to 2500 mL/min.5.4 Dry or Wet Positive Disp