ASTM E2125-07

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:E2125–07
Standard Guide for
Microcrystal Testing in the Forensic Analysis of
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Phencyclidine and Its Analogues
This standard is issued under the fixed designation E2125; 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 adequately gained 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 phencyclidine and its analogues.
1. Scope priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
1.1 This guide describes some standard procedures appli-
cable to the analysis of phencyclidine and its analogues using
2. Terminology
microcrystal tests.
2.1 Definitions:
1.2 Theseproceduresareapplicabletophencyclidmeandits
2.1.1 aggregation—the collecting of units or parts into a
analogues which are present in solid dosage form or in a liquid
mass or whole.
form. They are not typically applicable to the analysis of
2.1.2 birefringence—property of some crystals having more
phencyclidine and its analogues in biological samples.
than one refractive index.This will result in interference colors
1.3 This guide offers an organized collection of information
which are viewed through a polarized light microscope.
or a series of options and does not recommend a specific
2.1.3 grains—thick tablets having nearly equal width,
course of action. This document cannot replace education or
breadth, and thickness.
experience and should be used in conjunction with professional
2.1.4 habit—the external morphology of the crystal.
judgment. Not all aspects of this guide may be applicable in all
2.1.5 microdrop—a small drop of liquid that would fit on
circumstances. This ASTM standard is not intended to repre-
theendofastandardsize,flattenedtoothpick.Theapproximate
sent or replace the standard of care by which the adequacy of
volume of this drop would be 10 to 25 microliters.
a given professional service must be judged, nor should this
2.1.6 nails—a skeleton of some kinds of triangles, elon-
document be applied without consideration of a project’s many
gated, usually pointed with a short head usually thicker or
unique aspects. The word “Standard” in the title of this
broader.
document means only that the document has been approved
2.1.7 needles (acicular)—long, thin crystals with pointed
through the ASTM consensus process.
ends.
1.4 This standard does not purport to address all of the
2.1.8 nuggets—irregularly formed grains without sharp
safety concerns, if any, associated with its use. It is the
faces or edges.
responsibility of the user of this standard to establish appro-
2.1.9 pliers—crystals resembling pliers, generally
X-shaped.
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This guide is under the jurisdiction of ASTM Committee E30 on Forensic
2.1.10 razor blades—thin oblong crystals with length about
Sciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.
twice the width, resembling a safety razor blade.
Current edition approved March 1, 2007. Published March 2007. Originally
2.1.11 sheaves—elongated crystals form two opposite fans
approved in 2001. Last previous edition approved in 2001 as E2125 – 01. DOI:
10.1520/E2125-07. from the same joining point.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E2125–07
2.1.12 skeletal crystal—a crystal in which all of the spaces 8. Calibration and Standardization
in the crystal lattice are not occupied.
8.1 The reagents utilized for these microcrystal tests are to
2.1.13 spindles—shorter than course needles, but more
be tested for reliability using authenticated phencyclidine or its
substantial cross-section.
analogues and negative controls following the prescribed
procedure. Only when it is determined that the reagents are
3. Summary of the Technique
producing the expected response may the reagents be used in
3.1 Asmall sample of the material containing the suspected
the testing procedure.
phencyclidine or its analogues is dissolved in a dilute acid and
the appropriate precipitating reagent is added. The crystals that
9. Procedure
are formed are observed and distinguished utilizing a light
9.1 Potassium Permanganate:
microscope.
9.1.1 Place a small sample (a fe
...