ASTM_E_1763_-_06.pdf

Designation:E1763 06Standard Guide forInterpretation and Use of Results from InterlaboratoryTesting of Chemical Analysis Methods1This standard is issued under the fixed designation E1763;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 guide covers procedures to help a task groupinterpret interlaboratory study(ILS)statistics to state precisionand accuracy of a test method and make judgments concerningits range of use.1.2 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:2D6512 Practice for Interlaboratory Quantitation EstimateE135 Terminology Relating to Analytical Chemistry forMetals,Ores,and Related MaterialsE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE1763 Guide for Interpretation and Use of Results fromInterlaboratory Testing of Chemical Analysis MethodsE1914 Practice for Use of Terms Relating to the Develop-ment and Evaluation of Methods for Chemical Analysis3.Terminology3.1 For definitions of terms used in this guide,refer toTerminology E135.3.2 For descriptions of terms used in this guide,refer toPractice E1914.4.Significance and Use4.1 A written test method is subjected to an ILS to evaluateits performance.The ILS produces a set of statistical estimatesthat depend upon the method,but also are influenced by thelaboratories and test materials involved in the study.For thatreason,the ILS task group must interpret these estimates,aidedby this guide and using analytical judgment,to decide if themethod is suitable to be balloted for publication as a standard.The task group may use this guide to help them prepare theprecision and bias statements that are a required part of themethod.5.Interlaboratory Studies5.1 The following statement is required in each test method:5.1.1 This test method has been evaluated in accordancewith Practice E1601 and Guide E1763.Unless otherwise notedin the precision and bias section,the lower limit in the scope ofeach method specifies the lowest analyte content that may beanalyzed with acceptable error(defined as a nominal 5%riskof obtaining a 50%or larger relative difference in results onthe same test sample in two laboratories).NOTE1this guide has been found to be useful for calculation of theinterlaboratory quantitation estimate in accordance with Practice D6512,using known reference values in place of the measured values forapplication to that practice.It has been found necessary to replace the zerovalue for the blank with a very small number in order to apply this practiceto that method to avoid the divide by zero computational error.6.Required Statistical Information6.1 A task group satisfies the requirement for statisticalinformation if the method includes a table of the ILS statisticsprepared in accordance with 6.2 and 6.3 and a summarystatement selected from the model statements in Section 9.Ifthe task group wishes to provide further statistical information,it may do so in accordance with the provisions of Section 7.6.2 Variability DataList the variability statistics for eachanalyte in a separate table arranged by increasing analytecontent.List the number of independent data sets used in thecalculations and the ILS statistics calculated in accordancewith Practice E1601.Where appropriate,list the material typeand reference material identification.Follow the examples ofTable 1,Table 2,and Table 3.1This guide is under the jurisdiction of ASTM Committee E01 on AnalyticalChemistry for Metals,Ores and Related Materials and is the direct responsibility ofSubcommittee E01.22 on Laboratory Quality.Current edition approved Nov.1,2006.Published November 2006.Originallyapproved in 1995.Last previous edition approved in 2003 as E1763 98(2003).DOI:10.1520/E1763-06.2For 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.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.6.2.1 If the analytical method includes optional conditionsextending the analyte range(for example,decreased sampleportions or multiple calibration curves,)list the ILS statisticsfor each option separately as shown in Table A3.1 and TableA3.3.6.3 Bias DataIf the ILS includes one or more testmaterials having an accepted reference value,include theaccepted value(s)and b-value(s)as shown in Table 3.7.Models for