ASTM_D_3920_-_12.pdf

Designation:D392012Standard Test Method forStrontium in Water1This standard is issued under the fixed designation D3920;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 dissolvedand total recoverable strontium in water and wastewater byatomic absorption spectroscopy.1.2 The test method is applicable in the range from 0.1 to 1mg/L of strontium.The range may be extended by dilution ofthe original sample.1.3 Round-robin data were obtained in natural and reagentwater matrices.It is the users responsibility to ensure thevalidity of the test method for waters of untested matrices.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are mathematical conversions and may not beexact equivalents;therefore,each system shall be used inde-pendently of the other.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.Specific precau-tionary statements are given in and.2.Referenced Documents2.1 ASTM Standards:2D1129 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 ConduitsD4691 Practice for Measuring Elements in Water by FlameAtomic Absorption SpectrophotometryD4841 Practice for Estimation of Holding Time for WaterSamples Containing Organic and Inorganic ConstituentsD5810 Guide for Spiking into Aqueous SamplesD5847 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Water Analysis3.Terminology3.1 Definitions:For definitions of terms used in this testmethod,refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 total recoverable strontium,nan arbitrary analyticalterm relating to the forms of strontium that are determinable bythe digestion procedure described in this test method.3.2.2 laboratory control sample,na solution with a certi-fied concentration of the strontium.4.Summary of Test Method4.1 Strontium is determined by atomic absorption spectro-photometry.The sample is aspirated into an air-acetylene flamefollowing the addition of lanthanum chloride/potassium chlo-ride solution.Samples containing particulate matter that mayclog the aspirator capillary or burner,thus producing inaccurateresults,are filtered through a 0.45-m membrane filter prior totesting.5.Significance and Use5.1 Although most potable supplies contain little strontium,some well waters in the midwestern part of the United Stateshave levels as high as 39 mg/L.35.2 This test method affords a reliable means of accuratelydetermining strontium and correcting calcium results obtainedby the methods cited in 6.2.6.Interferences6.1 Chemical interference caused by silicon,aluminum,andphosphate is controlled by adding lanthanum chloride.Potas-sium chloride is added to suppress the ionization of strontium.NOTE1Anitrous oxide-acetylene flame has been used successfully bysome to remove chemical interferences.6.2 Strontium chemically resembles calcium and causes apositive error in gravimetric and titrimetric methods for cal-cium determination.1This 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 Sept.1,2012.Published September 2012.Originallyapproved in 1980.Last previous edition approved in 2002 as D3920 02(2007)E01.DOI:10.1520/D3920122For 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.DOI:10.1520/D3920-02R07E01.3Standard Method for the Examination of Water and Wastewater,14th Ed.American Public Health Assn.,Washington,DC 20005.*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 7.Apparatus7.1 Atomic Absorption Spectrophotometer for use at 460.7nm.A general guide for the use of flame atomic absorptionapplications is given in Practice D4691.NOTE2The manufacturers instructions should be followed forsetting instrumental parameters.7.2 Strontium Hollow-Cathode Lamp.8.Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents sh