1、Designation: E 2027 05Standard Practice forConducting Proficiency Tests in the Chemical Analysis ofMetals, Ores, and Related Materials1This standard is issued under the fixed designation E 2027; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice provides direction for organizing andconducting proficiency test programs in an
3、alytical chemistryfor metals, ores, and related materials. It is consistent withISO/IEC Guide 43 and Guide E 1301. It does not address theselection and use of proficiency testing schemes by accreditingbodies.2. Referenced Documents2.1 ASTM Standards:2E 135 Terminology Relating to Analytical Chemistr
4、y formetals, Ores, and Related MaterialsE 826 Practice for Testing Homogeneity of Materials for theDevelopment of Reference MaterialsE 1187 Terminology Relating to Conformity AssessmentE 1301 Guide for Proficiency Testing by InterlaboratoryComparisonsE 1724 Guide for Testing and Certification of Met
5、al andMetal-Related Reference Materials2.2 ISO Standards:3ISO 17025 General Requirements for the Competence ofCalibration and Testing LaboratoriesISO Guide 43 Proficiency Testing by Interlaboratory Com-parisonsISO Guide 9000 Quality Management and Quality SystemElements3. Terminology3.1 DefinitionsF
6、or formal definitions related to laboratoryaccreditation, Terminology E 1187 applies.3.2 For other definitions of terms used in the practice, referto Terminology E 135.4. Significance and Use4.1 This practice sets the basic requirements for proficiencytest programs in the chemical analysis of metals
7、, ores, andrelated materials. It does not set specific procedural require-ments, but does establish a framework for particular programs,including those with either small or large numbers of partici-pants.4.1.1 WARNING: The data from proficiency testing pro-grams must never be used to assign certific
8、ation values to thematerials used in the program. The elements of a properlyconceived and implemented certification program are de-scribed in detail in Guide E 1724.4.2 Most accreditation bodies require that laboratories par-ticipate regularly in proficiency testing programs that they haveaccepted f
9、or the purpose. Therefore, it is essential that eachprogram comply with accepted principles 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
10、the test item, the method in use and the number oflaboratories participating. The most common 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 of themater
11、ial from which the participants test materials are takenbe sufficiently homogeneous so that any 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 t
12、heassigned value(s) to give an indication of the performance ofthe individual laboratories and the group as a whole.5.2 In some cases, separate portions of previously certifiedreference materials are circulated.6. Organization and Design6.1 Framework:1This practice is under the jurisdiction of ASTM
13、Committee E01 on AnalyticalChemistry of Metals, Ores, and Related Materials and is the direct responsibility ofSubcommittee E01.22 on Laboratory Quality.Current edition approved May 1, 2005. Published July 2005. Originally approvedin 1999. Last previous edition approved in 1999 as E 2027 99.2For ref
14、erenced 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.3Available from American National Standards Institute (ANSI), 25 W. 4
15、3rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.1 The design stage of any proficiency testing programrequires the input of technical experts, statisticians and aprogram coordinator to ensure
16、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 confusion about its objectives. A plan shall beestablished and documented (see
17、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 and otherpersonnel involved in the design and operation of the profi-ciency prog
18、ram,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 and address of the laboratory or labora-tories performing the various parts of the
19、 program (for ex-ample, sampling, sample processing, homogeneity testing andassigning values) and a description of the market to be served,6.1.2.6 The nature of the test material(s) and test(s) selected,as well as a short description of the considerations underlyingthese choices,6.1.2.7 A descriptio
20、n 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 deadlines ofthe proficiency program including the date(s) for the testing tobe condu
21、cted 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 measurements(ASTM test methods, laboratory standard procedures/methods,etc.),6.1.2.12
22、 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 extent to which the test results,and the conclusions that will be based on t
23、he 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 of interlaboratory com-parisons. They shall possess appropriate technical, st
24、atisticaland 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 coordinator shall enlist some professionals to act as anadvisory group. The fu
25、nctions 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 interlaboratory comparisonsorganized by other bodies,6.2.2.3 Evaluate proficie
26、ncy test results of participatinglaboratories,6.2.2.4 Provide advice to any body assessing the technicalcompetence of participating laboratories, both on the resultsobtained during a proficiency test program, and how thoseresults should be used with other aspects of laboratory evalu-ations,6.2.2.5 P
27、rovide 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 entry and statisticalanalyses and provide timely and valid results. Procedur
28、es 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 analysis techniques tobe used shall be documented together with a short des
29、criptionof the background to their selection. Further details of commonstatistical procedures and treatment of proficiency testing dataare discussed in Annex A1.6.4.2 Careful consideration shall be given to the followingmatters and their interactions: the repeatability and reproduc-ibility of the te
30、st(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 repeat testsor measurements to be carried out on each sample; theprocedures to be us
31、ed to estimate the assigned value; proce-dures to be used to identify outliers; and, potential bias in thetest methods employed.6.5 Test Materials Preparation:6.5.1 Preparation of test materials may either be outsourcedor undertaken by the coordinator. The organization preparingthe test material sha
32、ll 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 effects ofambient conditions shall be considered.6.5.3 The test materials or mate
33、rials to be distributed in theprogram shall be similar in nature to those routinely tested byparticipating laboratories.6.5.4 The number of test materials to be distributed maydepend on whether there is a requirement to cover a range ofcompositions.E20270526.5.5 The assigned value(s) shall not be di
34、sclosed to theparticipants until after the results have been collated. However,in some cases it may be appropriate to advise target rangesprior 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 te
35、st materials may be useful as qualitycontrol materials, test samples for interlaboratory tests of newtest methods, or training aids for laboratories after results fromparticipants have been evaluated.6.6 Test Materials Management:6.6.1 Procedures for sampling, randomizing, transporting,receiving, id
36、entifying, labelling, storing and handling of testmaterials shall be documented.6.6.2 Where bulk material is prepared for a proficiency test,it shall be sufficiently homogeneous for each test parameter sothat all laboratories will receive test materials that do not differsignificantly in the paramet
37、ers to be measured. The coordinatorshall clearly state the procedure used to establish the homoge-neity of the test item (see A1.4). Homogeneity testing shall beconducted prior to the dispatch of the test materials to theparticipating laboratories.6.6.3 Where applicable, the coordinating laboratory
38、shallalso provide evidence that the test materials are sufficientlystable to ensure that they will not undergo any significantchange throughout the conduct of the proficiency test. Whenunstable analytes need to be assessed, it may be necessary forthe coordinating organization to prescribe a date by
39、which thetesting shall be completed, including required special pretest-ing procedures.6.6.4 Coordinators shall consider any hazards that the testmaterials might pose and take appropriate action to advise anyparty that might be at risk (for example, test material distribu-tors, testing laboratories,
40、 etc.).6.7 Choice of Test Method:6.7.1 The coordinator may instruct participants to use aspecified test method. 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 P
41、articipants may be able to use the test method of theirchoice, which is consistent with routine procedures used 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 o
42、fparticipants results to compare and comment on the testmethods.7. Operation and Reporting7.1 Coordination and DocumentationThe 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 suppleme
43、nted by, a quality manual(see Annex A2).7.2 Instructions:7.2.1 Detailed instructions covering all aspects of the 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
44、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 andtiming of testing.7.2.3 Specific instructions on the recording and reporting
45、oftest or calibration results shall also be supplied (for example,units, number of significant figures, reporting basis, resultdeadlines, etc.).7.2.4 Participants shall be advised to treat proficiency test-ing items as if they were routine tests (unless there are somespecial requirements in the desi
46、gn of the proficiency test whichmay require departure from this principle). They shall also beadvised to avoid collusion with other participants.7.2.5 Participants shall be advised to ensure that theirlaboratory capabilities are compatible with the protocols andtest samples provided by the programs.
47、 Incompatibility be-tween the program and its participants capabilities can lead toinappropriate indicators of poor performance.7.3 Packaging and Transportation:7.3.1 The coordinator of the program shall ensure thatpackaging and methods of transport are adequate and able toprotect the stability and
48、characteristics of the test materials.There may be certain restrictions on transportation such asdangerous goods regulations, or customs requirements. Insome cases, the laboratories themselves also take responsibilityfor the transport of the items, particularly in sequential mea-surement comparisons
49、 programs.7.3.2 All appropriate customs declaration forms shall becompleted by the coordinator to ensure that delays in customsclearance are minimized. The program shall comply withnational and international regulations applicable to test itemtransport.7.4 Data Analysis and Records:7.4.1 The results received from the participating laborato-ries shall be entered and analyzed and then reported as soon aspracticable. It is essential that procedures are implemented tocheck the validity of data entry and transfers and subsequentstatistical analysis. Data sheets, computer back-up file
