1、Designation:E196911Standard Guide forMicrocrystal Testing in Forensic Analysis ofMethamphetamine and Amphetamine1This standard is issued under the fixed designation E1969;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of la
2、st revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONMicrocrystal tests are primarily chemical-precipitation tests in which a light microscope is used toobserve and distinguish
3、the different types of crystals formed.These tests require skill and expertiseon the part of the analyst that can be gained adequately only through appropriate training andexperience in their use.These tests should not be attempted by those who are unfamiliar with themfor use in the analysis of meth
4、amphetamine or amphetamine.1.Scope1.1 This guide describes some standard procedures appli-cable to the analysis of methamphetamine and amphetamineusing microcrystal tests(1-6).21.2These procedures are applicable to methamphetamineand amphetamine,which are present in solid dosage form or aninjectable
5、 liquid form.These procedures are not typicallyapplicable to the analysis of methamphetamine and amphet-amine in biological samples.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard cannot replace knowledge,sk
6、ill,or abilityacquired through appropriate education,training,and experi-ence and should be used in conjunction with sound profes-sional judgment.1.5 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 standar
7、d to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:3E1459 Guide for Physical Evidence Labeling and RelatedDocumentationE1492 Practice for Receiving,Documenting,Storing,andRetrieving
8、Evidence in a Forensic Science LaboratoryE1732 Terminology Relating to Forensic ScienceE2329 Practice for Identification of Seized DrugsE2548 Guide for Sampling Seized Drugs for Qualitative andQuantitative Analysis3.Terminology3.1 For definitions of terms used in this standard,refer toTerminology E1
9、732.3.2 Definitions of Terms Specific to This Standard:3.2.1 aggregation,nthe collecting of units or parts into amass or whole.3.2.2 birefringence,nproperty of some crystals,havingmore than one refraction index;this property will result ininterference colors,which are viewed through a polarized ligh
10、tmicroscope.3.2.3 blades,nbroad,flat,elongated crystals.3.2.4 grains,nthick tablets having nearly equal width,breadth and thickness.3.2.5 habit,nthe external morphology of the crystal.1This guide is under the jurisdiction of ASTM Committee E30 on ForensicSciences and is the direct responsibility on
11、Subcommittee E30.01 on Criminalistics.Current edition approved March 1,2011.Published April 2011.Originallyapproved in 1998.Last previous edition approved in 2006 as E1969 06.DOI:10.1520/E1969-11.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.3For refer
12、enced 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshoho
13、cken,PA 19428-2959.United States1 3.2.6 microdrop,na small drop of liquid that would fit onthe end of a standard size,flattened toothpick;the approximatevolume of this drop would be 10 to 25 L.3.2.7 needles(acicular),nlong,thin crystals with pointedends.3.2.8 plates,nblades with nearly equal length
14、and breadthand of a thickness substantially less than the width.3.2.9 rods,nlong,thin crystals with squared off ends.3.2.10 tablets,nplates with appreciable thickness but lessthan the length or breadth.4.Summary of the Technique4.1 A small sample of the material containing the suspectedmethamphetami
15、ne or amphetamine is dissolved in an appro-priate acid and the appropriate precipitating reagent is added.The crystals that are formed are observed and distinguishedutilizing a light microscope.4.2 If the proper formation of crystals is inhibited by thepresence of diluents,a purification of the samp
16、le based on thevolatility of methamphetamine and amphetamine may beperformed.5.Significance and Use5.1 This technique produces a chemical-precipitation reac-tion between methamphetamine or amphetamine and the pre-cipitating reagent.The habit and the aggregation of the crystalsformed may be used to distinguish methamphetamine andamphetamine from other drugs.6.Interferences6.1 Diluents/AdulterantsDiluents/adulterants present incombination with methamphetamine or amphetamine in thesample to be test
