1、Designation:D625915(Reapproved 2019)An American National StandardStandard Practice forDetermination of a Pooled Limit of Quantitation for a TestMethod1This standard is issued under the fixed designation D6259;the number immediately following the designation indicates the year oforiginal adoption or,
2、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 the use of standard regressiontechniques and data from an interlab
3、oratory study to determinea lower quantitative limit for a test method.This determinedlower limit represents the numerical limit at or above which thetest results are considered to be quantitatively meaningful forcommerce or regulatory activities by this practice.It is definedby this standard as the
4、 pooled limit of quantitation(PLOQ)forthe test method.1.2 This practice is applicable to test methods that arecapable of producing numerical test results close to zero.Examples are those test methods that determine quantitativelythe concentration of analyte(s)near zero.1.3 This international standar
5、d was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenc
6、ed Documents2.1 ASTM Standards:2D6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.
7、Terminology3.1 Definitions:3.1.1 repeatability conditions,nconditions under whichtest results are obtained with the same test method in the samelaboratory by the same operator with the same equipment in theshortest practical period of time using test units or testspecimens taken at random from a sin
8、gle quantity of materialthat is as nearly homogeneous as possible.NOTE1By in the shortest practical period of time is meant that thetest results,at least for one material,are obtained in a time period not lessthan in normal testing and not so long as to permit significant change intest material,equi
9、pment,or environment.See Terminology E456.3.2 Definitions of Terms Specific to This Standard:3.2.1 pooled limit of quantitation(PLOQ),nlevel ofproperty or concentration for a test method at which the ratio:10 pooled repeatability standard deviation of results for aconcentration level/concentration l
10、evel=1.3.2.1.1 DiscussionQuantitative test results obtained usinga test method at or below its PLOQ is expected to have anuncertainty of 630%or greater at the 95%confidence level.3.2.2 pooled repeatability standard deviation,nthe statis-tically pooled standard deviation for results obtained underrep
11、eatability conditions over multiple operators/laboratoriesfor a sample that is obtained in accordance with PracticeD6300 or other equivalent Interlaboratory Study(ILS)analysis(for example,Practice E691,ISO 4259).3.2.3 laboratory limit of quantitation(LLOQ),nlevel ofproperty or concentration for a te
12、st method at which the ratio:10 repeatability standard deviation of results for a concen-tration level determined in a single laboratory/concentrationlevel=1.3.2.3.1 DiscussionQuantitative test results obtained bythis single laboratory at or below its LLOQ is expected to havean uncertainty of 630%or
13、 greater at the 95%confidencelevel.3.3 Acronyms:3.3.1 ILS,ninterlaboratory study.1This practice is under the jurisdiction of Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.94 on Coordinating Subcommittee on Quality Assurance and S
14、tatistics.Current edition approved May 1,2019.Published June 2019.Originallyapproved in 1998.Last previous edition approved in 2015 as D6259 15.DOI:10.1520/D6259-15R19.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Boo
15、k of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized pr
16、inciples on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 3.3.2 LLOQ,nlaboratory limit of quanitation.3.3.3 PLOQ,npooled limit of quantitation.4.Summary of Practice4.1 Statistically pooled repeatability standard deviationsfrom multiple laboratories for at least seven samples meetingthe requirements in Section 6 are obtained.4.2 An
