ASTM E2548-2011 Standard Guide for Sampling Seized Drugs for Qualitative and Quantitative Analysis《药物定性和定量分析采样获取的标准指南》.pdf

1、Designation: E2548 11Standard Guide forSampling Seized Drugs for Qualitative and QuantitativeAnalysis1This standard is issued under the fixed designation E2548; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis

2、ion. 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 covers minimum considerations for samplingof seized drugs for qualitative and quantitative analysis.2. Referenced Doc

3、uments2.1 ASTM Standards:2E105 Practice for Probability Sampling of MaterialsE122 Practice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE141 Practice for Acceptance of Evidence Based on theResults of Probability SamplingE1732 Te

4、rminology Relating to Forensic ScienceE2329 Practice for Identification of Seized DrugsE2334 Practice for Setting an Upper Confidence Bound Fora Fraction or Number of Non-Conforming items, or a Rateof Occurrence for Non-conformities, Using Attribute Data,When There is a Zero Response in the Sample2.

5、2 ISO Standards:3ISO 3534-1 Statistics Vocabulary and Symbols Part 1:Probability and General Statistical TermsISO 3534-2 Statistics Vocabulary and Symbols Part 2:Statistical Quality Control3. Significance and Use3.1 This guide provides information for the sampling ofseized-drug submissions.3.2 The p

6、rincipal purpose of sampling in the context of thisguide is to answer relevant questions about a population byexamination of a portion of the population. For example:What is the net weight of the population?What portion of the units of a population can be said to contain agiven drug at a given level

7、 of confidence?3.3 By developing a sampling strategy and implementingappropriate sampling schemes, as illustrated in Fig. 1,alaboratory will minimize the total number of required analyti-cal determinations, while ensuring that all relevant legal andscientific requirements are met.4. Sampling Strateg

8、y4.1 A sampling strategy is highly dependent on the purposeof the investigation, the original question, and the ultimate useof the results. Laws and legal practices form the foundation ofmost strategies and shall be taken into account when designinga sampling scheme. Therefore, specific sampling str

9、ategies arenot defined in this guide.4.2 The laboratory has the responsibility to develop its ownstrategies consistent with these recommendations. It is recom-mended that the following key points be addressed:4.2.1 Sampling may be statistical or non-statistical.NOTE 1For the purpose of this guide, t

10、he use of the term statistical ismeant to include the notion of an approach that is probability-based.4.2.1.1 In many cases, a non-statistical approach may suf-fice. The sampling plan shall provide an adequate basis foranswering questions of applicable law. For example,Is there a drug present in the

11、 population?Are statutory enhancement levels satisfied by the analysis of aspecified number of units?4.2.1.2 If an inference about the whole population is to bedrawn from a sample, then the plan shall be statistically basedand limits of the inference shall be documented.4.2.2 Statistically selected

12、units shall be analyzed to meetPractice E2329 if statistical inferences are to be made about thewhole population.5. Sampling Scheme5.1 The sampling scheme is an overall approach that in-cludes population determination, selection of the sampling planand procedure and, when appropriate, sample reducti

13、on prior toanalysis (Fig. 2).1This guide is under the jurisdiction of ASTM Committee E30 on ForensicSciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved Sept. 1, 2011. Published October 2011. Originallyapproved in 2007. Last previous version app

14、roved in 2007 as E2548 07. DOI:10.1520/E2548-11.2For 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.3Available fr

15、om International Organization for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.ch.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Population Determination:5.2.1 The popula

16、tion determination shall take into accountall typical forms and quantities in which exhibits may appear.5.2.2 A population can consist of a single unit or multipleunits.FIG. 1 Relationship of Various Levels Required in SamplingFIG. 2 Example of a Sampling SchemeA Decision FlowchartE2548 1125.2.3 A m

17、ultiple unit population shall consist of items thatare similar in relevant visual characteristics.SAMPLING PLAN5.3 There are numerous sampling plans used in the forensicanalysis of drugs that are applicable to single and multiple unitpopulations.5.4 When a single unit or bulk population is to be ana

18、lyzed,the issue of homogeneity shall be addressed within the sam-pling plan.5.4.1 One sample is sufficient if the bulk material is homo-geneous. Analysts can make bulk material homogeneous.5.4.2 If the bulk material is not homogeneous, severalsamples from different locations may be necessary to ensu

19、rethat the test results are representative of the bulk material andto avoid false negative results.5.5 Depending upon the inference to be drawn from theanalysis for a multiple unit population, the sampling plan maybe statistical or non-statistical.5.5.1 Statistical approaches are applicable when inf

20、erencesare made about the whole population. For example:The probability that a given percentage of the population containsthe drug of interest or is positive for a given characteristic.The total net weight of the population is to be extrapolated from theweight of a sample.5.5.1.1 Published examples

21、of statistical approaches involv-ing general considerations:(1) Practice E105.(2) Practice E141.(3) Terminology E1732.(4) Guidelines on Representative Drug Sampling.4(5) ISO 3534-1.(6) ISO 3534-2.5.5.1.2 Published examples of statistical approaches involv-ing the hypergeometric, normal, and other di

22、stributions from afrequentist perspective:(1) Frank, et al., Journal of Forensic Sciences.5(2) Guidelines on Representative Drug Sampling.4(3) Practice E2334.(4) Practice E122.5.5.1.3 Published examples of statistical approaches involv-ing the hypergeometric, normal, and other distributions from aBa

23、yesian perspective:(1) Coulson, et al., Journal of Forensic Sciences.6(2) Guidelines on Representative Drug Sampling.45.5.2 Non-statistical approaches are appropriate if no infer-ence is to be made about the whole population.5.5.2.1 Published examples:(1) The “square root method.”7(2) Methods listed

24、 in “Arbitrary Sampling” in Guidelineson Representative Drug Sampling.45.5.2.2 Selection of a single unit from a multiple unitpopulation may be appropriate under certain circumstances (forexample, management directives and legislative or judicialrequirements, or both).5.6 Sampling Procedure:5.6.1 Es

25、tablish the procedure for selecting the number ofunits that will comprise a sample.5.6.1.1 For non-statistical approaches, select a sample ap-propriate for the analytical objectives.5.6.1.2 For statistical approaches it is recommended thatrandom sampling be conducted.5.6.2 Select a Random Sample:5.6

26、.2.1 A random sample is one selected without bias.Computer generated random numbers or random number tablesare commonly employed for such tasks and these should beincluded in the sampling plan.5.6.2.2 Random sampling of items using random numbertables may not be practical in all cases. In these inst

27、ances, analternate sampling plan shall be designed and documented toapproach random selection. A practical solution involves a“black box” method, which refers to one that will prevent thesampler from consciously selecting a specific item from thepopulation (that is, all units are placed in a box and

28、 the samplesfor testing are selected without bias). Random sampling isdiscussed in the following references:(1) Practice E105.(2) Frank, et al., Journal of Forensic Sciences.5(3) ISO 3534-1.(4) ISO 3534-2.5.7 Sample ReductionSample reduction may be applied incases where the weight or volume of the s

29、elected units is toolarge for laboratory analysis (Fig. 2, insert A).6. Analysis6.1 Statistically Selected Sample(s)In accordance with4.2.2, it is recommended that each unit comprising the samplebe analyzed to meet Practice E2329 if statistical inferences areto be made about the whole population.6.2

30、 Non-statistically Selected Sample(s)Practice E2329shall be applied to at least one unit of the sample.7. Documentation7.1 Inferences based on use of a sampling plan and con-comitant analysis shall be documented.8. Reporting8.1 Sampling information shall be included in reports.8.1.1 Statistically Se

31、lected Sample(s)Reporting statisticalinferences for a population is acceptable when testing isperformed on the statistically selected units as stated in 4.1above. The language in the report must make it clear to thereader that the results are based on a sampling plan.8.1.2 Non-Statistically Selected

32、 Sample(s)The languagein the report must make it clear to the reader that the resultsapply to only the tested units. For example, 2 of 100 bags wereanalyzed and found to contain Cocaine.4Guidelines on Representative Drug Sampling, European Network of ForensicScience Institutes (ENFSI), 2004, http:/w

33、ww.ENFSI.org.5Frank et al., “Representative Sampling of Drug Seizures in Multiple Contain-ers,” Journal of Forensic Sciences, , Vol 36, No. 2, 1991, pp. 350357.6Coulson et al., “How Many Samples from a Drug Seizure Need to BeAnalyzed?,” Journal of Forensic Sciences, Vol 46, No. 6, 2001, pp. 14561461

34、.7Recommended Methods for Testing Opium, Morphine and Heroin: Manual forUse by National Drug Testing Laboratories, United Nations Office on Drugs andCrime, 1998.E2548 1139. Keywords9.1 analytical method; qualitative method; quantitativemethod; sampling; seized drug analytical methodASTM Internationa

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