1、Designation: C1068 03 (Reapproved 2011)Standard Guide forQualification of Measurement Methods by a LaboratoryWithin the Nuclear Industry1This standard is issued under the fixed designation C1068; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、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 provides guidance for selecting, validating,and qualifying measurement methods whe
3、n qualification 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 inte
4、nded to assure 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
5、7Control 8Personnel 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 limit
6、ations prior to use.2. Referenced Documents2.1 ASTM Standards:2C1009 Guide for Establishing a Quality Assurance Programfor Analytical Chemistry Laboratories Within the NuclearIndustryC1128 Guide for Preparation of Working Reference Mate-rials for Use in Analysis of Nuclear Fuel Cycle MaterialsC1156
7、Guide for Establishing Calibration for a Measure-ment Method Used to Analyze Nuclear Fuel Cycle Mate-rialsC1210 Guide for Establishing a Measurement System Qual-ity Control Program for Analytical Chemistry LaboratoriesWithin the Nuclear IndustryC1297 Guide for Qualification of Laboratory Analysts fo
8、rthe Analysis of Nuclear Fuel Cycle Materials3. 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 c
9、riteria 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 nucl
10、ear materials. Strict requirements for the control andaccountability of nuclear materials are imposed on the users ofthose materials. Therefore, when analyses are made by a1This guide is under the jurisdiction of ASTM Committee C26 on Nuclear FuelCycle and is the direct responsibility of Subcommitte
11、e C26.08 on Quality Assur-ance, Statistical Applications, and Reference Materials.Current edition approved June 1, 2011. Published June 2011. Originallyapproved in 1986. Last previous edition approved in 2003 as C1068 03. DOI:10.1520/C1068-03R11.2For referenced ASTM standards, visit the ASTM website
12、, 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.FIG. 1 Quality Assurance of Analytical Laboratory Data1Copyright ASTM International, 100 Barr Harbor Drive, PO Box
13、C700, West Conshohocken, PA 19428-2959, United States.laboratory to support a project such as the fabrication ofnuclear fuel materials, various performance requirements maybe imposed on the laboratory. One such requirement is oftenthe use of qualified methods. Their use gives greater assurancethat t
14、he 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.4.2 This guide provides guidance for qualifying measure-ment methods and for mainta
15、ining 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-ness of qualification is not reduced when applying thesepractices selectively. The
16、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 a method for a specific application,there should be assurance that the method has
17、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 capability is required within a laboratory.5.1.2 Measurement methods generally can be
18、 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 usage, and5.1.2.3 Those having limited use, for example, those usedonly by a few labor
19、atories 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 if it isa published standard or if it is capable of producing the leastbias and be
20、st 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 placed on which method is used.5.2 Recommended Practices for Method Selection:5.2.1 Tec
21、hnical 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 should not be adverselyaffected by components in the matrix of the material to beana
22、lyzed. 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 or electrical/electronicconditions should be considered in the selection process.5.
23、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 used to measureimpurities in materials since impurity concentrations mayfluctuate
24、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 reliably shouldbe clearly established (detection limit).5.2.4 Reliability of MethodThe
25、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 of the data and they should be based onthe concentration levels of the constituents
26、 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. This may bethe case when the method has had limited use or it is beingconsidered for a
27、 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 andqualification process, but it can prevent wasted effort fromattempts to qualify i
28、nadequate 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 method capability and to determine if themethod can be properly applied as intended.
29、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 procedure if necessary. The result of thevalidation process will be either the rejecti
30、on 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 no assurance that a laboratory canactually obtain the performance expected from th
31、e 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 Qualification requires having a laboratory demonstratethat a method can produce acceptable data
32、 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 data are evaluated by the person or organizationthat is responsible for approving
33、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 time. Demonstration could also include producingother evidence such as appropriate l
34、iterature references that themethod is in fact applicable to the material to be analyzed.7.2 Recommended Practices:C1068 03 (2011)27.2.1 ProceduresThe use of a method to make a labora-tory measurement involves taking discrete actions in a specificorder. Any change in an action or in the order may pr
35、oduceunsatisfactory 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 and editorial reviews,and should be approved by appropriate management. Ap
36、provalby the user of the data to be produced also may be required.Procedures prepared in accordance with Guide C1009 willmeet these criteria.7.2.2 Method Performance RequirementsTo provide ac-ceptable data, the method must be capable of meeting perfor-mance requirements for bias, precision, and rang
37、e. 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 are the primary source ofinformation on which the performance requirements
38、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 number of analysts orinstruments, or both, as well as the concentration range o
39、finterest.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 composition or properties of testmaterials should be defined by measurements tra
40、ceable tocertified reference materials. See Guide C1128.7.2.3.1 Major ConstituentsWhen the method is to be usedto determine a major constituent (for example, uranium inuranium oxide), a single test material may be specified. Theconcentration of the constituent in this test material shouldapproximate
41、 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 approving quali-fication should know the value (see 7.2.4.4). The calibration
42、standard should be specified. See Guide C1156.7.2.3.2 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 criteria given in 7.2.3.1 of this guide. Another should beused to demonstrate th
43、e 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 testmaterials would serve to demonstrate the range of the method.When a method req
44、uires one or more standards for calibration,the calibration standard(s) that will be used should be specified.See Guide C1156.7.2.4 Qualification RequirementsA procedure to be fol-lowed during demonstration should be established. The proce-dure that will govern qualification should include the follo
45、wingcriteria: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 not qualifying the method isacceptably small when the true bias is zero. The pl
46、an 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 procedure.7.2.4.2 PrecisionThe precision requirement should state avalue of the true st
47、andard deviation (larger than zero) that isboth desirable and practical to maintain together with an upperlimit, above which the true standard deviation would beunacceptable.Astatistical sampling and hypothesis testing planshould then be developed such that: the risk of qualifying amethod is accepta
48、bly 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 plan wouldinclude the number of analyses of a test material required tocontrol t
49、hese 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 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 dat
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