ASTM_D_6508_-_15.pdf

Designation:D650815Standard Test Method forDetermination of Dissolved Inorganic Anions in AqueousMatrices Using Capillary Ion Electrophoresis and ChromateElectrolyte1This standard is issued under the fixed designation D6508;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.Scope*1.1 This test method covers the determination of the inor-ganic anions fluoride,bromide,chloride,nitrite,nitrate,ortho-phosphate,and sulfate in drinking water,wastewater,and otheraqueous matrices using capillary ion electrophoresis(CIE)with indirect UV detection.See Figs.1-6.1.2 The test method uses a chromate-based electrolyte andindirect UV detection at 254 nm.It is applicable for thedetermination or inorganic anions in the range of 0.1 to 50mg/L except for fluoride whose range is 0.1 to 25 mg/L.1.3 It is the responsibility of the user to ensure the validityof this test method for other anion concentrations and untestedaqueous matrices.NOTE1The highest accepted anion concentration submitted forprecision and bias extend the anion concentration range for the followinganions:Chloride to 93 mg/L,Sulfate to 90 mg/L,Nitrate to 72 mg/L,andortho-phosphate to 58 mg/L.1.4 The values stated in SI units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.5 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:2D1066 Practice for Sampling SteamD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3856 Guide for Management Systems in LaboratoriesEngaged in Analysis of WaterD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water AnalysisD5905 Practice for the Preparation of Substitute WastewaterF488 Test Method for On-Site Screening of HeterotrophicBacteria in Water(Withdrawn 2005)33.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard,refer toTerminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 capillary ion electrophoresis,nan electrophoretictechnique in which a UV-absorbing electrolyte is placed in a 50m to 75 m fused-silica capillary.3.2.1.1 DiscussionVoltage is applied across the capillarycausing electrolyte and anions to migrate towards the anodeand through the capillarys UV detector window.Anions areseparated based upon the differential rates of migration in theelectrical field.Anion detection and quantitation are basedupon the principles of indirect UV detection.3.2.2 electrolyte,na combination of a UV-absorbing saltand an electroosmotic-flow modifier placed inside thecapillary,used as a carrier for the analytes,and for detectionand quantitation.3.2.2.1 DiscussionThe UV-absorbing portion of the saltmust be anionic and have an electrophoretic mobility similar tothe analyte anions of interest.3.2.3 electroosmotic flow(EOF),nthe direction and ve-locity of electrolyte-solution flow within the capillary under an1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.05 on Inorganic Constituentsin Water.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 2000.Last previous edition approved in 2010 as D6508 10.DOI:10.1520/D6508-15.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 applied electrical potential(voltage);the velocity and directionof flow is determined by electrolyte chemistry,capillary-wallchemistry,and applied voltage.3.2.4 electroosmotic-flow modifier(OFM),na cationicquaternary amine in the electrolyte that dynamically coats thenegatively charged silica wall giving it a net positive charge.3.2.4.1 DiscussionThis modifier reverses the direction ofthe electrolytes natural electroosmotic flow and directs itFIG.1 Electropher