1、Designation: C 1068 03Standard Guide forQualification of Measurement Methods by a LaboratoryWithin the Nuclear Industry1This standard is issued under the fixed designation C 1068; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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 guide provides guidance for selecting, validating,and qualifying measurement methods when qualification
3、 isrequired for a specific program. The recommended practicespresented in this guide provide a major part of a qualityassurance program for the laboratory data (see Fig. 1). Quali-fication helps to assure that the data produced will meetestablished requirements.1.2 The activities intended to assure
4、the quality of analyticallaboratory measurement data are diagrammed in Fig. 1. Dis-cussion and guidance related to some of these activities appearin the following sections:SectionSelection of Measurement Methods 5Validation of Measurement Methods 6Qualification of Measurement Methods 7Control 8Perso
5、nnel Qualification 91.3 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
6、 use.2. Referenced Documents2.1 ASTM Standards:C 1009 Guide for Establishing a Quality Assurance Pro-gram for Analytical Chemistry Laboratories Within theNuclear Industry2C 1128 Guide for Preparation of Working Reference Mate-rials for Use in the Analysis of Nuclear Fuel CycleMaterials2C 1156 Guide
7、for Establishing Calibration for a Measure-ment Method Used to Analyze Nuclear Fuel Cycle Mate-rials2C 1210 Guide for Establishing a Measurement SystemQuality Control Program for Analytical Chemistry Labo-ratories Within the Nuclear Industry2C 1297 Guide for Qualification of Laboratory Analysts fort
8、he Analysis of Nuclear Fuel Cycle Materials23. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 qualificationa formal process to provide a desiredlevel of confidence that measurement methods used willproduce data suitable for their intended use. The methods mustmeet established cr
9、iteria prior to use and must be used underconditions established for qualifications.4. Significance and Use4.1 Because of concerns for safety and the protection ofnuclear materials from theft, stringent specifications are placedon chemical processes and the chemical and physical proper-ties of nucle
10、ar materials. Strict requirements for the control andaccountability of nuclear materials are imposed on the users ofthose materials. Therefore, when analyses are made by alaboratory to support a project such as the fabrication ofnuclear fuel materials, various performance requirements may1This guide
11、 is under the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle and is the direct responsibility of Subcommittee C26.08 on Quality Assur-ance, Statistical Applications, and Reference Materials.Current edition approved July 10, 2003. Published August 2003. Originallyapproved in 1986. Last previ
12、ous edition approved in 1996 as C 1068 96e1.2Annual Book of ASTM Standards, Vol 12.01.FIG. 1 Quality Assurance of Analytical Laboratory Data1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.be imposed on the laboratory. One such requir
13、ement is oftenthe use of qualified methods. Their use gives greater assurancethat the data produced will be satisfactory for the intended useof those data. A qualified method will help assure that the dataproduced will be comparable to data produced by the samequalified method in other laboratories.
14、4.2 This guide provides guidance for qualifying measure-ment methods and for maintaining qualification. Even thoughall practices would be used for most qualification programs,there may be situations in which only a selected portion wouldbe required. Care should be taken, however, that the effective-
15、ness of qualification is not reduced when applying thesepractices selectively. The recommended practices in this guideare generic; based on these practices, specific actions should bedeveloped to establish a qualification program.5. Selection of Measurement Methods5.1 General:5.1.1 Before qualifying
16、 a method for a specific application,there should be assurance that the method has been properlyselected for that application. The guidance given in this sectioncan be used to assess the adequacy of the methods application.The guidance can also be used to select a new method when anew measurement ca
17、pability is required within a laboratory.5.1.2 Measurement methods generally can be classified asone of three types as follows:5.1.2.1 Those published as national or international consen-sus standards,5.1.2.2 Those established as acceptable for a specific appli-cation based on long-term and wide usa
18、ge, and5.1.2.3 Those having limited use, for example, those usedonly by a few laboratories or those that are relatively new.5.1.3 For some applications, there is a choice available oftwo or more acceptable methods. In those cases, one method isusually recognized as the reference method, particularly
19、 if it isa published standard or if it is capable of producing the leastbias and best precision.5.1.4 The selection of a method should be based on thecriteria in 5.2. In situations where a reference method and oneor more acceptable methods are available, there should be notechnical restrictions plac
20、ed on which method is used.5.2 Recommended Practices for Method Selection:5.2.1 Technical BasisThe method should be based onsound technology. This means that proven laboratory andinstrumental techniques are used in ways recognized andaccepted by the community of users.5.2.2 InterferencesThe method s
21、hould not be adverselyaffected by components in the matrix of the material to beanalyzed. Knowledge about the methods limitations and aboutthe composition of the material should be used to determine ifthe analysis will be affected by interferences. Other potentialinterferences such as environmental
22、or electrical/electronicconditions should be considered in the selection process.5.2.3 RangeThe method should be capable of respondingadequately across the range of concentration levels that will beencountered for the constituent to be measured. This require-ment is most often of concern for methods
23、 used to measureimpurities in materials since impurity concentrations mayfluctuate to a greater extent than other constituents. It isimportant that the measurement technique used discriminatesadequately between concentration levels encountered. Thelowest concentration level that can be measured reli
24、ably shouldbe clearly established (detection limit).5.2.4 Reliability of MethodThe method must be capableof producing data that will meet the bias and precisionrequirements established for the required analysis under theexpected conditions of use. The requirements are usuallyestablished by the user
25、of the data and they should be based onthe concentration levels of the constituents to be measured andon specification limits set for the constituents.6. Validation of Measurement Methods6.1 There are occasions when it is desirable to investigatethe applicability of a method to a particular use. Thi
26、s may bethe case when the method has had limited use or it is beingconsidered for a new or unique application. To provide someconfidence that a qualification effort would be successful, itmay be desirable to validate the application of the method.Validation is not a mandatory step in the selection a
27、ndqualification process, but it can prevent wasted effort fromattempts to qualify inadequate methods.6.2 Validation of a method is usually done by an analystunder controlled conditions. Basically, validation involvesinvestigating any or all of the selection criteria in 5.2. Theintent is to define me
28、thod capability and to determine if themethod can be properly applied as intended. If modification ofthe method is required for it to be applicable, validation willprovide the technical information needed for modification.Validation also provides the experience and information towrite a detailed pro
29、cedure if necessary. The result of thevalidation process will be either the rejection of a proposedmethod or confidence that it is acceptable for use as intended.7. Qualification of Measurement Methods7.1 General:7.1.1 Although a method is selected based on the criteria in5.2 of this guide, there is
30、 no assurance that a laboratory canactually obtain the performance expected from the method. Inaddition, there may not be sufficient assurance that the methodis in fact adequate for its intended use. To provide thoseassurances, demonstration is included in the qualificationprocess.7.1.2 Qualificatio
31、n requires having a laboratory demonstratethat a method can produce acceptable data under specifiedconditions of qualification. Demonstration must be done underactual operating conditions and not under ideal test conditions.A specified material is analyzed to produce a specified amountof data. These
32、 data are evaluated by the person or organizationthat is responsible for approving qualification. The procedureestablished for demonstration should include provisions forhandling failures in the demonstration and for repeating thedemonstration should the method not be used for a specifiedperiod of t
33、ime. Demonstration could also include producingother evidence such as appropriate literature references that themethod is in fact applicable to the material to be analyzed.7.2 Recommended Practices:7.2.1 ProceduresThe use of a method to make a labora-tory measurement involves taking discrete actions
34、 in a specificC1068032order. Any change in an action or in the order may produceunsatisfactory data. To minimize potential problems, written,stepwise procedures should be provided within the methods. Itis important that procedures are well-written, complete, andcorrect. They should receive technical
35、 and editorial reviews,and should be approved by appropriate management. Approvalby the user of the data to be produced also may be required.Procedures prepared in accordance with Guide C 1009 willmeet these criteria.7.2.2 Method Performance RequirementsTo provide ac-ceptable data, the method must b
36、e capable of meeting perfor-mance requirements for bias, precision, and range. Before alaboratory demonstrates its capability, these requirementsshould be clearly established (this should be done even beforea method is selected for use; see 5.2). Specifications estab-lished for a process or material
37、 are the primary source ofinformation on which the performance requirements are based.The performance requirements should be used to establishconditions required for qualification. Such conditions mayrequire a statistically designed experiment to allow for othersources of variability such as the num
38、ber of analysts orinstruments, or both, as well as the concentration range ofinterest.7.2.3 Test MaterialsThe material or materials that will beused for demonstration should be specified. The test materialsshould be as similar as possible to the material that will beanalyzed. When possible, the comp
39、osition or properties of testmaterials should be defined by measurements traceable tocertified reference materials. See Guide C 1128.7.2.3.1 Major ConstituentsWhen the method is to be usedto determine a major constituent (for example, uranium inuranium oxide), a single test material may be specified
40、. Theconcentration of the constituent in this test material shouldapproximate the specification value established for the con-stituent in the material to be analyzed. The concentration valueof the test material should not be given to the laboratory; onlythose responsible for evaluating the data and
41、approving quali-fication should know the value (see 7.2.4.4). The calibrationstandard should be specified. See Guide C 1156.7.2.3.2 ImpuritiesWhen the method is to be used todetermine an impurity, at least two test materials should bespecified. One should serve as a test standard, meeting thesame cr
42、iteria given in 7.2.3.1 of this guide. Another should beused to demonstrate the detection limit of the method. Whenpossible, the detection limit should be sufficiently below thespecification limit to determine whether or not the concentra-tion level of the impurity is within specification. Both test
43、materials would serve to demonstrate the range of the method.When a method requires one or more standards for calibration,the calibration standard(s) that will be used should be specified.See Guide C 1156.7.2.4 Qualification RequirementsA procedure to be fol-lowed during demonstration should be esta
44、blished. The proce-dure that will govern qualification should include the followingcriteria:7.2.4.1 BiasA statistical sampling and hypothesis testingplan should be developed such that the risk of qualifying amethod is acceptably small when the true bias exceeds thestated requirement and the risk of
45、not qualifying the method isacceptably small when the true bias is zero. The plan wouldinclude the number of analyses of a test standard required tocontrol these risks at acceptably small levels and would expressthe requirement for qualifying based on bias as a statisticalhypothesis testing procedur
46、e.7.2.4.2 PrecisionThe precision requirement should state avalue of the true standard deviation (larger than zero) that isboth desirable and practical to maintain together with an upperlimit, above which the true standard deviation would beunacceptable. A statistical sampling and hypothesis testing
47、planshould then be developed such that: the risk of qualifying amethod is acceptably small when the true standard deviationexceeds the specified upper limit, and the risk of not qualifyingthe method is acceptably small when the true standard devia-tion is less than or equal to the desired value. The
48、 plan wouldinclude the number of analyses of a test material required tocontrol these risks at acceptably small levels and would expressthe requirement for qualifying based on precision as a statis-tical hypothesis testing procedure.7.2.4.3 RangeA requirement, such as the following,should be stated
49、when range is of concern: “Data obtained fromthe analysis of test materials, including calibration standards,shall be submitted to demonstrate the range of the methodunder the specific conditions of qualification. The calibrationof the method should cover the expected range of concentra-tion.”7.2.4.4 Reporting DataThe agency to whom demonstra-tion data will be submitted should be specified. The agencycould be a person or group within or outside of the laboratory,depending upon the program or project requiring qualifiedmethods. The person or persons evaluating the data s
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