1、Designation: E 2548 07Standard Guide forSampling Seized Drugs for Qualitative and QuantitativeAnalysis1This standard is issued under the fixed designation E 2548; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. 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 covers minimum considerations for samplingof seized drugs for qualitative and quantitative analysis.2. Referenced
3、Documents2.1 ASTM Standards:2E 105 Practice for Probability Sampling Of MaterialsE 122 Practice for Calculating Sample Size to Estimate,With a Specified Tolerable Error, the Average for aCharacteristic of a Lot or ProcessE 141 Practice for Acceptance of Evidence Based on theResults of Probability Sa
4、mplingE 1732 Terminology Relating to Forensic ScienceE 2329 Practice for Identification of Seized DrugsE 2334 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 Respons
5、e in the Sample2.2 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 subm
6、issions.3.2 The principal 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
7、 at a given level 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.
8、 Sampling Strategy4.1 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, spec
9、ific sampling strategies 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
10、 of this guide, the 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 dr
11、ug present in the 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 Statis
12、tically selected units shall be analyzed to meetPractice E 2329 if statistical inferences are to be made aboutthe whole 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 appropria
13、te, sample reduction prior toanalysis (Fig. 2).5.2 Population Determination: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 March 1, 2007. Published April 2007.2For refe
14、renced 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 International Organization for Standardization (ISO),
15、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.5.2.1 The population determination shall take into accountall typical forms and quantities in which ex
16、hibits may appear.5.2.2 A population can consist of a single unit or multipleunits.5.2.3 A multiple unit population shall consist of items thatare similar in relevant visual characteristics.FIG. 1 Relationship of Various Levels Required in SamplingFIG. 2 Example of a Sampling SchemeA Decision Flowch
17、artE2548072Sampling 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 analyzed,the issue of homogeneity shall be addressed within the sam-pling plan.5.4.1 One s
18、ample 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 ensurethat the test results are representative of the bulk material andto avoid false negat
19、ive 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 inferencesare made about the whole population. For example:The probability that a given pe
20、rcentage 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 of statistical approaches involv-ing general considerations:(1) Practice E 105.(2) Prac
21、tice E 141.(3) Terminology E 1732.(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 distributions from afrequentist perspective:(1) Frank, et al, Journal of Forensic Scie
22、nces.5(2) Guidelines on Representative Drug Sampling.4(3) Practice E 2334.(4) Practice E 122.5.5.1.3 Published examples of statistical approaches involv-ing the hypergeometric, normal, and other distributions from aBayesian perspective:(1) Coulson, et al, Journal of Forensic Sciences.6(2) Guidelines
23、 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 in “Arbitrary Sampling” in Guidelineson Representative Drug Sampling.45.5.2.2 Selec
24、tion 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 Establish the procedure for selecting the number ofunits that will comprise a sample.5
25、.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:5.6.2.1 A random sample is one selected without bias.Computer generated random numbers
26、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 instances, analternate sampling plan shall be designed and documented toapproach random
27、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 the samplesfor testing are selected without bias). Random sampling isdiscussed in t
28、he following references:(1) Practice E 105.(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 selected units is toolarge for laboratory analysis (Fig. 2, insert A).6. Analysis6.1
29、Statistically Selected Sample(s)In accordance with4.2.2, it is recommended that each unit comprising the samplebe analyzed to meet Practice E 2329 if statistical inferences areto be made about the whole population.6.2 Non-statistically Selected Sample(s)Practice E 2329shall be applied to at least on
30、e unit of the sample.7. Documentation7.1 Inferences based on use of a sampling plan and con-comitant analysis shall be documented.8. Keywords8.1 analytical method; qualitative method; quantitativemethod; sampling; seized drug analytical method4Guidelines on Representative Drug Sampling, European Net
31、work of ForensicScience Institutes (ENFSI), 2004, (www.ENFSI.org).5“Representative Sampling of Drug Seizures in Multiple Containers,” Frank etal, Journal of Forensic Sciences, 1991, 36(2), pp. 350-357.6“How Many Samples from a Drug Seizure Need to Be Analyzed?” Coulson etal, Journal of Forensic Scie
32、nces, 2001, 46(6), pp. 1456-1461.7Recommended Methods for Testing Opium, Morphine and Heroin: Manual forUse by National Drug Testing Laboratories, United Nations Office on Drugs andCrime, 1998.E2548073ASTM International takes no position respecting the validity of any patent rights asserted in conne
33、ction with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsi
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35、nsideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100
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