1、Designation: D 6362 98 (Reapproved 2003)Standard Practice forCertificates of Reference Materials for Water Analysis1This standard is issued under the fixed designation D 6362; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 covers the information that must beprovided on certificates of analysis of reference materialsdesi
3、gnated to support ASTM methods. It provides end users ofthese materials with a defined set of data that is required to beon a certificate of analysis and provides information to assistthe end user in evaluating the independence of the material.Similarly, it provides the suppliers of reference materi
4、als witha consistent format for the presentation of certification data.1.2 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 th
5、e applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1129 Terminology Relating to WaterE 826 Practice for Testing Homogeneity of Materials for theDevelopment of Reference Materials2.2 ISO StandardsISO Guide 30 Terms and definitions used in connection w
6、ithreference materials3ISO Guide 31 Contents of certificates of reference materi-als3ISO Guide 35 Certification of reference materialsGeneraland statistical principles3ISO/REMCO N28033. Terminology3.1 DefinitionsFor definitions of terms used in this prac-tice, refer to Terminology D 1129 and ISO Gui
7、de 303.2 Definitions of Terms Specific to This Standard:3.2.1 prepared value, nthe best estimate of the concen-tration of a given analyte based upon the purity of rawmaterials and the method of preparation of the material.4. Significance and Use4.1 This practice is designed to assist suppliers and u
8、sers ofreference materials by identifying the information necessary onthe certificate of analysis of materials designated for use inASTM test methods. This practice is specifically designed toensure that materials suitable for use as either calibration orquality control standards are available. This
9、 practice does notdefine a specific certification protocol, but rather providesguidance in the development of adequate data to support theuse of the material as either a calibration or quality controlstandard. Suppliers are referred to ISO Guide 35 for guidelineson acceptable certification protocols
10、. End users are referred toISO Guide 31 for a more complete description of the elementsof typical certificates of analysis.5. Certificate of Analysis5.1 The certificate of analysis is a summary of the analysisperformed to support the designated use of the material. As asummary, the certificate must
11、be brief, but it must providesufficient information to allow the potential user of the materialto assess the suitability of the material for his intended use.Therefore, reference material suppliers are encouraged tosupply method information and analytical data in a summarythat clearly and unambiguou
12、sly allows the user to make aninformed decision about the suitability of the material. The useof terms as defined by ISO or ASTM is required.5.2 The certificate of analysis must be supported by acertification report for the material. The certification reportmust contain the details of the analyses p
13、erformed to developthe certified values reported on the certificate of analysis. Itmust contain the method(s) used for analysis, details of themethod of preparation, if appropriate, including gravimetricdata, supporting instrumental data, and the results of support-ing statistical analysis reported
14、on the certificate of analysis.The certification report must be provided to the end user of thematerial if requested.1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.02 on General Specifications,Technical Resources, and Stati
15、stical Methods.Current edition approved Aug. 10, 2003. Published November 2003. Originallyapproved in 1998. Last previous edition approved in 1998 as D 636298.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of
16、ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute, 11 W. 42nd St., 13thFloor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
17、United States.6. Certificate Headings6.1 The following sections detail the headings to be used onthe certificate of analysis. ASTM methods require the use of adiverse set of reference materials. Therefore, it is expected thatall headings will not be appropriate for all materials. However,exceptions
18、should be avoided in order to insure sufficientinformation for evaluation of materials. Therefore, each of thefollowing sections is designated as either mandatory or op-tional based upon ensuring a minimum data set. Appendix X1contains examples of typical certificates of analysis designed tomeet the
19、se requirements.6.1.1 Name and Address of Certifying Organization(Mandatory)This is the name and address of the organizationthat accepts responsibility for the information on the certificate.Organizations that provided analytical data or prepared thematerial may be provided elsewhere on the certific
20、ate.6.1.2 Material Identification (Mandatory)This sectionmust identify the material by name, as labeled, and mustinclude a lot or batch number that can be used to uniquelyidentify the material.6.1.3 Supplier of the Reference Material (Optional)If thesupplier of the reference material is different fr
21、om the certify-ing organization then this section should contain the name andaddress of the supplier of the material.6.1.4 Preparer of the Material (Optional)If the materialwas not prepared by the supplier or the certifying organization,then this section should include the name and address of thepre
22、parer of the material.6.1.5 Source of the Material (Mandatory)For a solutionstandard, or a matrix material, this section must identify thesource of the raw materials or the source of the matrix material,used in the preparation of the material. The supplier mayidentify the source of the material as p
23、roprietary. If the sourceof the material is declared to be proprietary then the suppliermust provide contact information on the certificate in order toassist end users.6.1.6 Description and Intended Use of the Material(Optional)Most reference materials are designed to be usedfor a specific purpose.
24、This section should designate theintended use of the material. It should also contain a suffi-ciently detailed description of the material to allow the user toestimate its usability in their application.This material is designed to be used in D XXXX as a cali-bration standard. The material was prepa
25、red in Type Iwater to contain 1 mg/ml of the certified components.6.1.7 Stability, Transportation, and Storage Conditions(Mandatory)Any known temperature, storage, or transporta-tion factors that could influence the stability of the materialmust be identified. It is required that the supplier identi
26、fyproper storage and handling conditions that are necessary toinsure usability for the expected life of the material. Similarly,the supplier should identify the period of time for which theywill assume responsibility for the validity of the certifiedvalues.6.1.8 Instructions for Use (Mandatory)If th
27、e materialrequires special handling, dilution, drying, or any other specificmanipulation in order to achieve the certified values, theseprocedures must be clearly identified in this section.6.1.9 Method of Preparation (Optional)If the method ofpreparation gives the user an idea of the care taken by
28、thesupplier, significant details of the preparation procedure maybe included in this section.6.1.10 State of Homogeneity (Mandatory)As it relates tothe certification of reference materials, homogeneity refers tothe analysis and demonstration of uniformity of final packagedunits. Every certificate mu
29、st contain a homogeneity statement.This section must include the sampling, analytical method(s),and procedure used to evaluate the homogeneity of thematerial. Appendix X2 provides a suggested procedure forhomogeneity testing and references to alternative internation-ally accepted homogeneity testing
30、 procedures. If the homoge-neity of the material has not been determined, then this must bestated on the certificate.6.1.11 Certified Property Values and Their Associated Un-certainties (Mandatory)The information in this sectionshould be given in tabular form with appropriate subsectionheadings. The
31、 minimum information to be provided includesthe property, the certified value of the property, the associateduncertainty, and the method of analysis. Since the certificate isa synopsis of the certification report, suppliers are encouragedto identify the method of analysis by appropriate standardmeth
32、od number. Modifications or exceptions to the givenmethod may be annotated in another section of the certificate.Likewise, if the values certified are dependent upon certainconditions, for example temperature, these can be identified infootnotes to the table. Values for properties that are not certi
33、fiedshould be included in a separate table.NOTE 1Several different procedures can be used to certify referencematerials. These depend upon the nature of the material to be certified andthe technical capability of the supplier and certifying body. The three mostcommon procedures for certification are
34、 detailed in Section 7. Theprocedure used to certify property values must be provided under theheading of statistical estimators and uncertainty referenced below.6.1.12 Uncertified Properties (Optional)Many timesproperties of the material are known but without sufficientaccuracy or precision to supp
35、ort certification. These valuesmay be reported by the supplier in this section to assist the userin the selection of appropriate materials.6.1.13 Values Obtained by Individual Laboratories or Meth-ods (Optional)Many times materials are certified based uponinterlaboratory studies or by using several
36、different methods ofanalysis. In these cases, this section can be used to reportindividual data by laboratory or method where appropriate. Ifthe supporting data are too voluminous to report in this section,a reference to the certification report may be made here toidentify the source and availabilit
37、y of supporting data.6.1.14 Statistical Estimator and Uncertainty (Mandatory)The meaning and nature of the certified values must be given,that is, the statistical estimator must be named. Where theestimator cannot be named then the mathematical expressionused in calculation must be presented.The cer
38、tified values are based upon the unweightedmean of nine independent measurements by eachmethod reported.D 6362 98 (2003)2The certified values are based upon a biweight estimateof the mean of the center 50 % of the reported data us-ing the Tukey Bisquare Procedure with a tuning constantof 3.97. Detai
39、ls of the procedure may be obtained fromthe certifier.NOTE 2The method used to estimate the uncertainty associated withthe certified value of the property is important. Therefore, the suppliermust identify the factors considered in estimation of uncertainty and themethod used for calculation. If the
40、 uncertainty is estimated by a coveragefactor, such as 2s/=n , then the formula and the values for each variablein the formula must be provided on the certificate.6.1.15 Measurement Methods Used for Certification(Optional)This section should provide the exceptions to, ormodifications of, the standar
41、d or reported method(s) used forcertification. Sufficient details of the analysis must be providedin the certification report to allow independent verification ofthe analytical values. However, only those details which areessential to reproducibility need to be reported.6.1.16 Identification of Anal
42、ysts or Laboratories(Optional)This section may be used to identify the contri-bution of individual analysts or laboratories to the certificationeffort. The identification of analysts or laboratories may assistthe user in establishing the quality of the certification data.6.1.17 Legal Notice (Optiona
43、l)Disclaimers or legal limi-tations of liability for the information on the certificate shouldappear in this section.6.1.18 Reference to Certification Report (Mandatory)Thecertification report supporting the summary provided on thecertificate must be unambiguously identified in this section.Instruct
44、ions for obtaining the full certification report must beprovided in this section.6.1.19 Signature of Certifying Offcer (Mandatory)It isrequired that the officer of the certifying body who acceptsresponsibility for the information on the certificate sign thecertificate.6.1.20 Annex (Optional)The anne
45、x may be used by thesupplier to supply additional information about the material orits certification. It may contain graphical presentations or otherinformation not appropriate in the body of the certificate.7. Certification Procedures7.1 The certification procedure is the protocol used todevelop ce
46、rtification data. It is independent of the method(s)used for certification and is usually dependent upon the natureof the material to be certified. The procedure used to certify thereference material is usually dependent upon the nature of thematerial and the property to be certified. In the case of
47、 a pureor neat compound to be used for preparation of calibrationmaterials, the properties of interest are confirmation of identityand an accurate assay of the material. In the case of a preparedcalibration solution, the property of interest is the best estimateof the concentration of the analyte in
48、 the solvent. In the case ofa quality control material, the property of interest is theperformance of the material in a particular method.7.1.1 Most reference materials, and properties of interest,are certified by one of the following three procedures: 1) directcomparison method, most frequently use
49、d for assay work, oranalysis of calibration materials where a suitable NIST stan-dard reference material (SRM) exists; 2) verification of theprepared value, used to certify the prepared value of a materialif an SRM is not available for direct comparison; and, 3)interlaboratory certification procedure, used to establish typicalmethod performance values or an assigned value for matrixmaterials.7.1.2 In the case of the direct comparison method, thecertified value is based upon analysis to a known calibrantprepared from an SRM or other national standard. In these
