1、Designation: E2027 171Standard Practice forConducting Proficiency Tests in the Chemical Analysis ofMetals, Ores, and Related Materials1This standard is issued under the fixed designation E2027; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 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.1NOTESection 3 corrected editorially in January 2018.1. Scope1.1 This practice provides direction for organ
3、izing andconducting proficiency test programs in analytical chemistryfor metals, ores, and related materials. It is consistent withISO/IEC 17043 and Guide E1301. It does not address theselection and use of proficiency testing schemes by accreditingbodies.1.2 This international standard was developed
4、 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. Referenced Document
5、s2.1 ASTM Standards:2E135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE826 Practice for Testing Homogeneity of a Metal Lot orBatch in Solid Form by Spark Atomic Emission Spec-trometryE1301 Guide for Proficiency Testing by InterlaboratoryComparisons (Withdrawn 2
6、012)3E2972 Guide for Production, Testing, and Value Assignmentof In-House Reference Materials for Metals, Ores, andOther Related Materials2.2 ISO Standards:4ISO 9001 Quality ManagementISO 13528 Statistical Methods for Proficiency Testing byInterlaboratory ComparisonISO/IEC 17025 General Requirements
7、 for the Competenceof Calibration and Testing LaboratoriesISO/IEC 17043 Conformity Assessment General Require-ments for Proficiency Testing3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this practice, refer toTerminology E135.3.2 Definition of Term Specific to This Practice:3.2
8、.1 assigned value, nvalue that serves as a declared oragreed-upon reference for comparison, normally derived fromor based on experimental work of a national or internationalorganization.3.2.1.1 DiscussionThe assigned value is given to a prop-erty or constituent of a reference material or proficiency
9、 testmaterial through technical and statistical evaluation of testresults.4. Significance and Use4.1 This practice sets the basic requirements for proficiencytest programs in the chemical analysis of metals, ores, andrelated materials. It does not set specific proceduralrequirements, but does establ
10、ish a framework for particularprograms, including those with either small or large numbersof participants.4.2 The data from proficiency testing programs can be usedfor value assignments for in-house reference materials devel-oped in accordance with Guide E2972.1This practice is under the jurisdictio
11、n 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. 15, 2017. Published December 2017. Originallyapproved in 1999. Last previous edition approved in 2009 as E
12、2027 09. DOI:10.1520/E2027-17E01.2For 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 o
13、f this historical standard is referenced onwww.astm.org.4Available from International Organization for Standardization (ISO), ISOCentral Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,Geneva, Switzerland, http:/www.iso.org.Copyright ASTM International, 100 Barr Harbor Drive, PO B
14、ox C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by
15、the World Trade Organization Technical Barriers to Trade (TBT) Committee.14.3 Most accreditation bodies require that laboratories par-ticipate regularly in proficiency testing programs that they haveaccepted for this purpose. Therefore, it is essential that eachprogram comply with accepted principle
16、s including technicalrequirements, statistical procedures (see Annex A1), and qual-ity management (see Annex A2).5. Types of Proficiency Testing5.1 Proficiency testing techniques vary depending on thenature of the test item, the method in use and the number oflaboratories participating. The most com
17、mon approach in-volves randomly selected sub-samples from a source of mate-rial being distributed simultaneously to participating testinglaboratories for concurrent testing. It is essential that all thematerial from which the participants test materials are takenbe sufficiently homogeneous so that a
18、ny results later identifiedas outliers should not be attributed to any significant test itemvariability. After completion of the testing, the results arereturned to the coordinating body, and compared with theassigned value(s) or to the mean and standard deviationsobtained from a statistical analysi
19、s of the data to give anindication of the performance of the individual laboratories andthe group as a whole.5.2 In some cases, separate portions of certified referencematerials are circulated.6. Organization and Design6.1 Framework:6.1.1 The design stage of any proficiency testing programrequires t
20、he input of technical experts, statisticians and aprogram coordinator to ensure its success and smooth opera-tion.6.1.2 The coordinator, in consultation with these otherpersonnel, develops a program appropriate to the particularproficiency test.Aproficiency test program shall be designed toavoid any
21、 confusion about its objectives. A plan shall beestablished and documented (see Annex A2) before the start ofthe program and shall include the following information:6.1.2.1 The name and the address of the organizationconducting the proficiency program,6.1.2.2 The name and address of the coordinator
22、and otherpersonnel involved in the design and operation of the profi-ciency program,6.1.2.3 The nature and the purpose of the proficiencyprogram,6.1.2.4 Aprocedure for the manner in which the participantsare selected, or criteria that need to be met before participationis allowed,6.1.2.5 The name an
23、d address of the laboratory or labora-tories performing the various parts of the program (forexample, sampling, sample processing, homogeneity testingand assigning values) and a description of the market to beserved,6.1.2.6 The nature of the test material(s) and test(s) selected,as well as a short d
24、escription of the considerations underlyingthese choices,6.1.2.7 A description of the manner in which the testmaterials are obtained, processed, checked and transported,6.1.2.8 The time schedule for the various phases of theproficiency testing,6.1.2.9 The expected initial and target dates or deadlin
25、es ofthe proficiency program including the date(s) for the testing tobe conducted by the participants,6.1.2.10 For ongoing programs, the frequency at which testmaterials are distributed,6.1.2.11 Information on methods or procedures which par-ticipants may need to use to perform the tests or measurem
26、ents(ASTM test methods, laboratory standard procedures/methods,etc.),6.1.2.12 An outline of the statistical analysis to be usedincluding the determination of assigned value(s) and anyoutlier detection techniques,6.1.2.13 The basis for performance evaluation techniques,and6.1.2.14 Adescription of the
27、 extent to which the test results,and the conclusions that will be based on the outcome of theproficiency tests, are to be made public.6.2 Staff:6.2.1 The staff shall include, or collaborate closely with,those holding adequate qualifications and experience in thedesign, implementation and reporting
28、of interlaboratory com-parisons. They shall possess appropriate technical, statisticaland administrative skills.6.2.2 The operation of specific interlaboratory comparisonsrequires the guidance of persons with detailed technical knowl-edge and experience of the test methods involved. To this endthe c
29、oordinator shall enlist some professionals to act as anadvisory group. The functions of this advisory group may beto:6.2.2.1 Develop and review procedures for the planningexecution, analysis, reporting and monitoring the effectivenessof the proficiency testing program,6.2.2.2 Identify and evaluate i
30、nterlaboratory comparisonsorganized by other bodies,6.2.2.3 Evaluate proficiency test results of participatinglaboratories,6.2.2.4 Provide advice to anyone assessing the technicalcompetence of participating laboratories, both on the resultsobtained during a proficiency test program, and how thoseres
31、ults should be used with other aspects of laboratoryevaluations,6.2.2.5 Provide advice to participants who appear to expe-rience problems, and6.2.2.6 Resolve disputes between the coordinator and par-ticipants.6.3 Data Processing EquipmentEquipment shall be ad-equate to conduct all necessary data ent
32、ry and statisticalanalyses and provide timely and valid results. Procedures forchecking data entry shall be implemented and all software shallbe verified, supported and backed up. The storage and securityof data files shall be controlled.6.4 Statistical Design:6.4.1 The statistical model and data an
33、alysis techniques tobe used shall be documented together with a short descriptionof the background to their selection. Further details of commonE2027 1712statistical procedures and treatment of proficiency testing dataare discussed in Annex A1.6.4.2 Careful consideration shall be given to the follow
34、ingmatters and their interactions: the repeatability and reproduc-ibility of the test(s) involved; the smallest differences to bedetected between participating laboratories at a desired confi-dence level; the number of participating laboratories; thenumber of samples to be tested and the number of r
35、epeat testsor measurements to be carried out on each sample; theprocedures to be used to estimate the assigned value; proce-dures to be used to identify outliers and potential bias in the testmethods employed.6.5 Test Materials Preparation:6.5.1 Preparation of test materials may either be outsourced
36、or performed by the coordinator. The organization preparingthe test material shall have demonstrable competence to do so.6.5.2 Any conditions relating to the test materials that mayaffect the integrity of the interlaboratory comparison, such ashomogeneity, stability, possible damage in transit and e
37、ffects ofambient conditions shall be considered.6.5.3 The test materials or materials to be distributed in theprogram shall be similar in nature to those routinely tested byparticipating laboratories using the methods prescribed.6.5.4 The number of test materials to be distributed maydepend on wheth
38、er there is a requirement to cover a range ofcompositions.6.5.5 The assigned value(s) shall not be disclosed to theparticipants until after all the results have been collated, oruntil such time that no new results will be considered.However, in some cases it may be appropriate to advise targetranges
39、 prior to testing.6.5.6 Consideration may be given to preparation of addi-tional test materials other than those needed for the proficiencytest program. Surplus test materials may be useful as qualitycontrol materials, test samples for interlaboratory tests of newtest methods, or training aids for l
40、aboratories after results fromparticipants have been evaluated.6.6 Test Materials Management:6.6.1 Procedures for sampling, randomizing, transporting,receiving, identifying, labeling, storing and handling of testmaterials shall be documented.6.6.2 Where bulk material is prepared for a proficiency te
41、st,it shall be sufficiently homogeneous (based on evaluation byPractice E826) for each test parameter so that all laboratorieswill receive test materials that do not differ significantly in theparameters to be measured. An estimate of permissible varia-tion between results on different test portions
42、 (homogeneitytest) obtained by the same operator applying the same testmethod with the same apparatus under identical operatingconditions within short intervals of time can be obtained fromthe reproducibility limits. The coordinator shall clearly statethe procedure used to establish the homogeneity
43、of the test item(see A1.4). Homogeneity testing shall be conducted prior to thedispatch of the test materials to the participating laboratories.6.6.3 Where applicable, the coordinator shall also provideevidence that the test materials are sufficiently stable to ensurethat they will not undergo any s
44、ignificant change throughoutthe performance of the proficiency test. When unstable ana-lytes need to be assessed, it may be necessary for thecoordinating organization to prescribe a date by which thetesting shall be completed, including required special pretest-ing procedures.6.6.4 Coordinators shal
45、l consider any hazards that the testmaterials might pose and take appropriate action to advise anyparty that might be at risk (for example, test materialdistributors, testing laboratories, etc.).6.7 Choice of Test Method:6.7.1 The coordinator may instruct participants to use aspecified test method.
46、Such test methods are usually nationallyor internationally-accepted standard test methods, and willhave been validated by an appropriate procedure (for example,collaborative trial).6.7.2 Participants may be able to use the test method of theirchoice, which is consistent with routine procedures used
47、intheir laboratories. Where participants are free to use a testmethod of their own choice, coordinators shall request detailsof the test methods used to allow, where appropriate, the use ofparticipants results to compare and comment on the testmethods.7. Operation and Reporting7.1 Coordination and D
48、ocumentationThe day-to-day op-eration of a program shall be the responsibility of a coordina-tor. All practices and procedures shall be documented. Thesemay be incorporated in, or supplemented by, a quality manual(see Annex A2).7.2 Instructions:7.2.1 Detailed instructions covering all aspects of the
49、 pro-gram that should be followed by the participating laboratoriesshall be provided. These may be provided, for example, as anintegral part of a program protocol.7.2.2 Instructions shall include details concerning factorsthat could influence the testing of the supplied materials. Suchfactors shall include qualifications of operators, nature of thematerials, equipment status, selection of test procedures, tim-ing of testing, and specimen preparation.7.2.3 Specific instructions on the recording and reporting oftest or calibration results shall also be supplied. These ins
