ASTM E1969-19

Standard Practice for Microcrystal Testing in Forensic Analysis for Methamphetamine and Amphetamine

SIGNIFICANCE AND USE
5.1 This technique involves a chemical-precipitation reaction between methamphetamine or amphetamine and the precipitating reagent. The habit and the aggregation of the crystals formed could be used to distinguish methamphetamine and amphetamine from other drugs, as well as from each other.
SCOPE
1.1 This practice describes procedures applicable to the analysis of methamphetamine and amphetamine using microcrystal tests (1-6).2  
1.2 These procedures are applicable to methamphetamine and amphetamine, which are present in solid dosage form or an injectable liquid form. These procedures are not typically applicable to the analysis of methamphetamine and amphetamine in biological samples.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 These procedures could generate observations indicating a positive test for methamphetamine or amphetamine which could be incorporated into the analytical scheme as defined by the laboratory.  
1.5 This standard cannot replace knowledge, skills, or abilities acquired through appropriate education, training, and experience (see Practice E2326) and is to be used in conjunction with sound professional judgment by individuals with such discipline-specific knowledge, skills, and abilities.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2019
• ICS: 07.140 - Forensic science
• ICS: 11.100.99 - Other standards related to laboratory medicine
• Technical Committee: E30 - Forensic Sciences
• Drafting Committee: E30.01 - Criminalistics

Relations

• Refers: ASTM E1732-24 - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Feb-2024
• Refers: ASTM E1732-19 - Standard Terminology Relating to Forensic Science
• Effective Date: 15-Jan-2019
• Refers: ASTM E1732-18b - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Nov-2018
• Refers: ASTM E1732-18a - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Jun-2018
• Refers: ASTM E1732-18 - Standard Terminology Relating to Forensic Science
• Effective Date: 15-May-2018
• Refers: ASTM E1732-17 - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Sep-2017
• Refers: ASTM E2329-14 - Standard Practice for Identification of Seized Drugs
• Effective Date: 01-Dec-2014
• Refers: ASTM E1459-13 - Standard Guide for Physical Evidence Labeling and Related Documentation
• Effective Date: 15-Feb-2013
• Refers: ASTM E1732-12 - Standard Terminology Relating to Forensic Science
• Effective Date: 15-Jun-2012
• Refers: ASTM E1732-11a - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Oct-2011
• Refers: ASTM E1732-11b - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Oct-2011
• Refers: ASTM E2548-11e1 - Standard Guide for Sampling Seized Drugs for Qualitative and Quantitative Analysis
• Effective Date: 01-Sep-2011
• Refers: ASTM E2548-11 - Standard Guide for Sampling Seized Drugs for Qualitative and Quantitative Analysis
• Effective Date: 01-Sep-2011
• Refers: ASTM E1492-11 - Standard Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
• Effective Date: 01-Jun-2011
• Refers: ASTM E2764-11 - Standard Practice for Uncertainty Assessment in the Context of Seized-Drug Analysis (Withdrawn 2020)
• Effective Date: 01-Jun-2011

Overview

ASTM E1969-19: Standard Practice for Microcrystal Testing in Forensic Analysis for Methamphetamine and Amphetamine describes proven procedures for the use of microcrystal chemical-precipitation tests to analyze methamphetamine and amphetamine in solid dosage forms or injectable liquids. The standard establishes essential guidelines for forensic laboratories in performing, verifying, and documenting these analyses, supporting reliable drug identification. It is part of the broader guidance provided by ASTM for forensic drug analysis and is developed in line with international standards principles.

Key Topics

• Microcrystal Testing Practice: This standard details chemical-precipitation methods where suspected methamphetamine or amphetamine reacts with specific reagents, forming distinctive crystals observable under a light microscope. The formation, habit, and aggregation of these microcrystals can distinguish methamphetamine from amphetamine and from similar compounds.
• Scope of Application: Procedures apply to methamphetamine and amphetamine in solid or injectable liquid form. The method does not extend to biological samples.
• Professional Judgment and Competence: Successful microcrystal testing requires appropriate education, training, and laboratory skills. The standard must be used alongside relevant professional judgment as outlined in related practices such as ASTM E2326.
• Safety Considerations: The standard acknowledges that users must establish suitable safety, health, and environmental practices and comply with regulatory limitations.
• Result Documentation: Careful documentation, including photographic records of observed crystalline precipitates, is required for each analysis.
• Interferences: The standard covers the influence of adulterants or diluents, methods for purification, and troubleshooting situations where characteristic crystal formation is hindered.

Applications

• Forensic Drug Analysis: Microcrystal testing per ASTM E1969-19 is a rapid, reliable screening method commonly used in forensic science laboratories for identifying seized methamphetamine and amphetamine. The method is particularly valuable for distinguishing these drugs from other structurally related substances.
• Complementary Analytical Techniques: Positive results from microcrystal testing can become part of a forensic laboratory’s analytical scheme, supporting or directing further confirmatory tests as recommended by ASTM E2329 (Identification of Seized Drugs).
• Legal and Investigative Support: Accurate identification and documentation contribute evidence for criminal investigations and legal proceedings involving controlled substances.
• Educational and Training Uses: The practice provides a foundational skillset for training new forensic analysts in the discrimination and microscopic identification of illicit stimulants.

Related Standards

The effectiveness and reliability of microcrystal testing are supported by adherence to additional relevant ASTM standards, including:

• ASTM E1459: Guide for Physical Evidence Labeling and Related Documentation
• ASTM E1492: Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
• ASTM E1732: Terminology Relating to Forensic Science
• ASTM E2326: Practice for Education and Training of Seized-Drug Analysts
• ASTM E2329: Practice for Identification of Seized Drugs
• ASTM E2548: Guide for Sampling Seized Drugs for Qualitative and Quantitative Analysis
• ASTM E2764: Practice for Uncertainty Assessment in the Context of Seized-Drug Analysis

Practical Value

ASTM E1969-19 provides forensic chemists and laboratories with a well-vetted, systematic approach to microcrystal testing for methamphetamine and amphetamine. Its standardized procedures enable consistent, reproducible results and support the evidentiary chain of custody. By adhering to these guidelines, forensic laboratories ensure the quality, reliability, and legal defensibility of their drug analyses.

Keywords: microcrystal testing, forensic drug analysis, methamphetamine, amphetamine, ASTM E1969-19, chemical-precipitation, forensic laboratory standards

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1969 − 19 An American National Standard
Standard Practice for
Microcrystal Testing in Forensic Analysis for
Methamphetamine and Amphetamine
This standard is issued under the fixed designation E1969; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Microcrystal tests are primarily chemical-precipitation tests in which a light microscope is used to
observe and distinguish the different types of crystals formed. These tests require skill and expertise
on the part of the analyst that can be gained adequately only through appropriate training and
experience in their use. These tests should not be attempted by those who are unfamiliar with them
for use in the analysis of methamphetamine or amphetamine.
1. Scope 1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice describes procedures applicable to the
ization established in the Decision on Principles for the
analysis of methamphetamine and amphetamine using micro-
2 Development of International Standards, Guides and Recom-
crystal tests (1-6).
mendations issued by the World Trade Organization Technical
1.2 These procedures are applicable to methamphetamine
Barriers to Trade (TBT) Committee.
andamphetamine,whicharepresentinsoliddosageformoran
injectable liquid form. These procedures are not typically
2. Referenced Documents
applicable to the analysis of methamphetamine and amphet-
2.1 ASTM Standards:
amine in biological samples.
E1459Guide for Physical Evidence Labeling and Related
1.3 The values stated in SI units are to be regarded as
Documentation
standard. No other units of measurement are included in this
E1492Practice for Receiving, Documenting, Storing, and
standard.
Retrieving Evidence in a Forensic Science Laboratory
E1732Terminology Relating to Forensic Science
1.4 These procedures could generate observations indicat-
E2326Practice for Education and Training of Seized-Drug
ingapositivetestformethamphetamineoramphetaminewhich
Analysts
could be incorporated into the analytical scheme as defined by
E2329Practice for Identification of Seized Drugs
the laboratory.
E2548GuideforSamplingSeizedDrugsforQualitativeand
1.5 This standard cannot replace knowledge, skills, or
Quantitative Analysis
abilities acquired through appropriate education, training, and
E2764PracticeforUncertaintyAssessmentintheContextof
experience (see Practice E2326) and is to be used in conjunc-
Seized-Drug Analysis (Withdrawn 2020)
tion with sound professional judgment by individuals with such
discipline-specific knowledge, skills, and abilities.
3. Terminology
1.6 This standard does not purport to address all of the
3.1 Definitions:
safety concerns, if any, associated with its use. It is the
3.1.1 For definitions of terms used in this standard, refer to
responsibility of the user of this standard to establish appro-
Terminology E1732.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.2 Definitions of Terms Specific to This Standard:
This practice is under the jurisdiction of ASTM Committee E30 on Forensic
SciencesandisthedirectresponsibilityonSubcommitteeE30.01onCriminalistics. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2019. Published December 2019. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1998. Last previous edition approved in 2011 as E1969–11. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E1969-19. the ASTM website.
2 4
The boldface numbers in parentheses refer to a list of references at the end of The last approved version of this historical standard is referenced on
this standard. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1969 − 19
3.2.1 aggregation, n—the collecting of units or parts into a 7. Apparatus
mass or whole.
7.1 Astandard light microscope capable of varying magni-
3.2.2 birefringence, n—property of some crystals, those
fications including 100× is needed for viewing the crystals.
havingmorethanonerefractionindex;thispropertywillresult
This is the minimum equipment required. A polarized light
in interference colors, which are viewed through a polarized
attachment is not essential, but is desirable, because the heavy
light microscope.
metal crystals of methamphetamine and amphetamine are
birefringent.
3.2.2.1 birefringent, adj—material exhibiting birefringence.
7.1.1 Polarized Light Microscope (PLM), capable of vary-
3.2.3 blades, n—broad, flat, elongated crystals.
ingmagnificationsfrom40×to400×.Thefollowingaretypical
3.2.4 grains, n—thick tablets having nearly equal width,
accessoriesonaPLMandcouldbeuseful,butarenotrequired,
breadth and thickness.
to conduct microcrystalline testing: specialized rotating stage
3.2.5 habit, n—the external morphology of the crystal.
(360°) and compensator (retardation plate). Cross-polarizers
are verified by observing a black background when the
3.2.6 microdrop, n—a small drop of liquid that would fit on
polarizer and analyzer are in the optical path at 90 degrees to
theendofastandardsize,flattenedtoothpick;theapproximate
oneanother(forexample,polarizerisintheeast-westdirection
volume of this drop would be 10 to 25µL.
and the analyzer is in the north-south direction).
3.2.7 needles (acicular), n—long, thin crystals with pointed
7.1.2 The best practice for documenting the crystal forma-
ends.
tionresultsistotakeadigitalphotograph.Itisadvisedthatthe
3.2.8 plates, n—bladeswithnearlyequallengthandbreadth
minimum equipment required also has the capability of digital
and of a thickness substantially less than the width.
photography.
3.2.9 rods, n—long, thin crystals with squared off ends.
8. Reagents and Materials
3.2.10 tablets, n—plates with appreciable thickness but less
8.1 10 % Solution of Hydrochloric Acid (hereafter, dilute
than the length or breadth.
hydrochloric acid).
4. Summary of the Technique
8.2 Concentrated Phosphoric Acid.
4.1 Asmallamountoftestmaterialcontainingthesuspected
8.3 1.0 N to 10.0 N Sodium Hydroxide.
methamphetamine or amphetamine is dissolved in an appro-
8.4 Gold Chloride (HAuCl ) Solution, approximately 5%,
priate acid and the appropriate precipitating reagent is added.
inreagentgradewater.Goldchlorideinphosphoricacidalsois
The crystals that are formed are observed and distinguished
suitable; 1:2 5 % gold chloride/concentrated phosphoric acid.
utilizing a light microscope.
8.5 Platinum Chloride (H PtCl ) Solution, approximately
2 6
4.2 If the proper formation of crystals is inhibited by the
5%, in reagent grade water. Platinum chloride in phosphoric
presenceofdiluents,apurificationofthetestmaterialbasedon
acid also is suitable; 1:2 5 % platinum chloride/concentrated
the volatility of methamphetamine and amphetamine could be
phosphoric acid.
performed.
8.6 d-, l-, and dl- Amphetamine Standards.
5. Significance and Use
8.7 d-, l-, and dl- Methamphetamine Standards.
5.1 This technique involves a chemical-precipitation reac-
9. Sampling, Test Specimens, and Test Units
tion between methamphetamine or amphetamine and the pre-
cipitatingreagent.Thehabitandtheaggregationofthecrystals 9.1 The general handling and tracking of samples should
meetorexceedtherequirementsofPracticeE1492andGuides
formed could be used to distinguish methamphetamine and
amphetamine from other drugs, as well as from each other. E1459 and E2548.
10. Performance Verification
6. Interferences
10.1 Prior to use in casework, the reagents used for these
6.1 Diluents/Adulterants—Diluents/adulterants present in
microcrystal tests shall be tested for reliability using amphet-
combination with methamphetamine or amphetamine in the
amine and methamphetamine standards and negative controls
test material to be tested could inhibit crystal formation or
followingtheprescribedprocedure.Onlywhenitisdetermined
couldgeneratecrystalsthataredistortedorotherwiserendered
thatthereagentsareproducingtheexpectedresponsecouldthe
unidentifiable. Diluting the test material could reduce the
reagents be used in the testing procedure.
interference.The higher the concentration of the adulterant the
moredifficultitwillbetoobservecharacteristiccrystals.There 10.2 The microscope should be inspected, adjusted, and
couldbecaseswheredilutingthetestmaterialwouldnotwork. aligned to ensure it is in proper working order. This can be
In these instances, it will be necessary to separate the meth- confirmed during the testing of the standard. Perform the
amphetamine or amphetamine from the diluents/adulterants or analysis of unknown samples and standards under the same
to use other testing methods to analyze the methamphetamine microscope operating procedures (for example, use of cross
or amphetamine. polarizers).
E1969 − 19
11. Procedure 11.1.7.2 Add a small volume (approximately 1 to 2 drops)
of 1.0N to 10.0N sodium hydroxide, such that the test
11.1 Gold Chloride:
material is just covered.
11.1.1 Place a small amount ( approximately 1 mg) of test
11.1.7.3 Placeamicrodropofconcentratedphosphoricacid,
material on a microscope slide.
or gold chloride reagent containing phosphoric acid, on a slide
11.1.1.1 While the test material can be placed directly onto
and invert the slide over the basified test material such that the
theslide,itcouldalsobeintroducedontotheslidefromadilute
microdrop is over the spot well containing the test material.
solution of methanol or diethyl ether and allowing the solvent
11.1.7.4 Any amine present, including methamphetamine
to dry before continuing with the analysis.
and amphetamine, will be converted to the free base form.
11.1.2 Dissolve the test material in a few microdrops of
Many free bases are volatile at room temperature, and as they
dilute hydrochloric acid or concentrated phosphoric acid.
leave the solution, they will interact w
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1969 − 11 E1969 − 19
Standard GuidePractice for
Microcrystal Testing in Forensic Analysis offor
Methamphetamine and Amphetamine
This standard is issued under the fixed designation E1969; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Microcrystal tests are primarily chemical-precipitation tests in which a light microscope is used to
observe and distinguish the different types of crystals formed. These tests require skill and expertise
on the part of the analyst that can be gained adequately only through appropriate training and
experience in their use. These tests should not be attempted by those who are unfamiliar with them
for use in the analysis of methamphetamine or amphetamine.
1. Scope
1.1 This guidepractice describes some standard procedures applicable to the analysis of methamphetamine and amphetamine
using microcrystal tests (1-6).
1.2 These procedures are applicable to methamphetamine and amphetamine, which are present in solid dosage form or an
injectable liquid form. These procedures are not typically applicable to the analysis of methamphetamine and amphetamine in
biological samples.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 These procedures could generate observations indicating a positive test for methamphetamine or amphetamine which could
be incorporated into the analytical scheme as defined by the laboratory.
1.5 This standard cannot replace knowledge, skill,skills, or abilityabilities acquired through appropriate education, training,
and experience (see Practice E2326) and should is to be used in conjunction with sound professional judgment.judgment by
individuals with such discipline-specific knowledge, skills, and abilities.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
E1459 Guide for Physical Evidence Labeling and Related Documentation
E1492 Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
E1732 Terminology Relating to Forensic Science
E2326 Practice for Education and Training of Seized-Drug Analysts
E2329 Practice for Identification of Seized Drugs
E2548 Guide for Sampling Seized Drugs for Qualitative and Quantitative Analysis
This guidepractice is under the jurisdiction of ASTM Committee E30 on Forensic Sciences and is the direct responsibility on Subcommittee E30.01 on Criminalistics.
Current edition approved March 1, 2011Nov. 1, 2019. Published April 2011December 2019. Originally approved in 1998. Last previous edition approved in 20062011
as E1969 – 06.E1969 – 11. DOI: 10.1520/E1969-11.10.1520/E1969-19.
The boldface numbers in parentheses refer to a list of references at the end of this standard.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1969 − 19
E2764 Practice for Uncertainty Assessment in the Context of Seized-Drug Analysis
3. Terminology
3.1 For definitions of terms used in this standard, refer to Terminology E1732.Definitions:
3.1.1 For definitions of terms used in this standard, refer to Terminology E1732.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 aggregation, n—the collecting of units or parts into a mass or whole.
3.2.2 birefringence, n—property of some crystals, those having more than one refraction index; this property will result in
interference colors, which are viewed through a polarized light microscope.
3.2.2.1 birefringent, adj—material exhibiting birefringence.
3.2.3 blades, n—broad, flat, elongated crystals.
3.2.4 grains, n—thick tablets having nearly equal width, breadth and thickness.
3.2.5 habit, n—the external morphology of the crystal.
3.2.6 microdrop, n—a small drop of liquid that would fit on the end of a standard size, flattened toothpick; the approximate
volume of this drop would be 10 to 25 μL.
3.2.7 needles (acicular), n—long, thin crystals with pointed ends.
3.2.8 plates, n—blades with nearly equal length and breadth and of a thickness substantially less than the width.
3.2.9 rods, n—long, thin crystals with squared off ends.
3.2.10 tablets, n—plates with appreciable thickness but less than the length or breadth.
4. Summary of the Technique
4.1 A small sampleamount of thetest material containing the suspected methamphetamine or amphetamine is dissolved in an
appropriate acid and the appropriate precipitating reagent is added. The crystals that are formed are observed and distinguished
utilizing a light microscope.
4.2 If the proper formation of crystals is inhibited by the presence of diluents, a purification of the sample test material based
on the volatility of methamphetamine and amphetamine maycould be performed.
5. Significance and Use
5.1 This technique producesinvolves a chemical-precipitation reaction between methamphetamine or amphetamine and the
precipitating reagent. The habit and the aggregation of the crystals formed maycould be used to distinguish methamphetamine and
amphetamine from other drugs.drugs, as well as from each other.
6. Interferences
6.1 Diluents/Adulterants—Diluents/adulterants present in combination with methamphetamine or amphetamine in the sample
test material to be tested maycould inhibit crystal formation or result incould generate crystals that are distorted or otherwise
rendered unidentifiable. Diluting the test material could reduce the interference. The higher the concentration of the adulterant the
more difficult it will be to observe characteristic crystals. There could be cases where diluting the test material would not work.
In these instances, it will be necessary to separate the methamphetamine or amphetamine from the diluentsdiluents/adulterants or
to use other testing methods to analyze the methamphetamine or amphetamine.
7. Apparatus
7.1 A standard light microscope capable of varying magnifications including 100× is needed for viewing the crystals. This is
the minimum equipment required. A polarized light attachment is not essential, but is desirable, because the heavy metal crystals
of methamphetamine and amphetamine are birefringent.
7.1.1 Polarized Light Microscope (PLM), capable of varying magnifications from 40× to 400×. The following are typical
accessories on a PLM and could be useful, but are not required, to conduct microcrystalline testing: specialized rotating stage
(360°) and compensator (retardation plate). Cross-polarizers are verified by observing a black background when the polarizer and
analyzer are in the optical path at 90 degrees to one another (for example, polarizer is in the east-west direction and the analyzer
is in the north-south direction).
7.1.2 The best practice for documenting the crystal formation results is to take a digital photograph. It is advised that the
minimum equipment required also has the capability of digital photography.
8. Reagents and Materials
8.1 10 % Solution of Hydrochloric Acid.Acid (hereafter, dilute hydrochloric acid).
8.2 Concentrated Phosphoric Acid.
E1969 − 19
8.3 1.0 N to 10.0 N Sodium Hydroxide.
8.4 Gold Chloride (HAuCI(HAuCl ) Solution, approximately 5 %, in reagent grade water. Gold chloride in phosphoric acid also
is suitable.suitable; 1:2 5 % gold chloride/concentrated phosphoric acid.
8.5 Platinum Chloride (H PtC1PtCl ) Solution, approximately 5 %, in reagent grade water. Platinum chloride in phosphoric
2 6
acid also is suitable.suitable; 1:2 5 % platinum chloride/concentrated phosphoric acid.
8.6 Amphetamine Standard.d-, l-, and dl- Amphetamine Standards.
8.7 Methamphetamine Standard.d-, l-, and dl- Methamphetamine Standards.
9. Sampling, Test Specimens, and Text Units—Test Units
9.1 The general handling and tracking of samples should meet or exceed the requirements of Practice E1492 and Guides E1459
and E2548.
10. Calibration and StandardizationPerformance Verification
10.1 The reagents utilizedPrior to use in casework, the reagents used for these microcrystal tests are to shall be tested for
reliability using amphetamine and methamphetamine standards and negative controls following the prescribed procedure. Only
when it is determined that the reagents are producing the expected response maycould the reagents be used in the testing procedure.
10.2 The microscope should be inspected, adjusted, and aligned to ensure it is in proper working order. This can be confirmed
during the testing of the standard. Perform the analysis of unknown samples and standards under the same microscope operating
procedures (for example, use of cross polarizers).
E1969 − 19
11. Procedure
11.1 Gold Chloride:
11.1.1 Place a small sample, a few particles of powder, less than 1 mg, of the suspected methamphetamine or amphetamine
amount ( approximately 1 mg) of test material on a microscope slide.
11.1.1.1 While the test material can be placed directly onto the slide, it could also be introduced onto the slide from a dilute
solution of methanol or diethyl ether and allowing the solvent to dry before continuing with the analysis.
11.1.2 Dissolve the sample test material in a few microdrops of 10 % hydrochloridedilute hydrochloric acid or concentrated
phosphoric acid.
NOTE 1—The crystals tend to precipitate faster from the phosphoric acid. There also tends to be less interference when using the concentrated
phosphoric acid.
11.1.3 Add a few microdrops of 5 % gold chloride reagent to the edge of the acidtest solution on the microscope slide.
11.1.4 Observe the formation of the crystals using a properly aligned and adjusted light microscope. standard light microscope
or PLM. This observation can be done between crossed polarspolarizers if desired. If crossed polarspolarizers are to be used, orient
the polarizer in the used, verify cross-polarizers by observing a black background when the polarizer and analyzer are in the optical
path at 90 degrees to one another (for example, polarizer is in the east-west direction and the analyzer in the north-south direction,
verified by a black background. direction).
11.1.5 The crystals formed will depend on the drug present, as well as, the optical isomer present for the drug. The formations
Formation of crystals corresponding to those obtained with standards is are indicative of the presence of methamphetamine or
amphetamine in a pure or racemic mixture of optical isomers. The habit and aggregation of the resulting crystals that can be
expected for methamphetamineamphetamine and amphetaminemethamphetamine are as follows.follows:
11.1.5.1 d- or l-Amphetamine, produces long Long yellow rods or blades.blades are observed with d- or l-amphetamine.
11.1.5.2 d,l-Amphetamine, produces irregular Irregular blades, which have serrated edges and often will grow in groups of three
or more.more, are observed with d,l-amphetamine.
11.1.5.3 d- or l-Methamphetamine, produces long Long blades and jointed crystals. crystals are observed with d- or
l-methamphetamine. If these crysta
...