ASTM E2125-01

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Designation:E2125–01
Standard Guide for
Microcrystal Testing in the Forensic Analysis of
Phencyclidine and Its Analogues
This standard is issued under the fixed designation E 2125; 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 (e) 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 2.1.9 razor blades—thin oblong crystals with length about
twice the width, resembling a safety razor blade.
1.1 This guide describes some standard procedures appli-
2.1.10 sheaves—elongated crystals form two opposite fans
cable to the analysis of phencyclidine and its analogues using
from the same joining point.
microcrystal tests.
2.1.11 skeletal crystal—a crystal in which all of the spaces
1.2 Theseproceduresareapplicabletophencyclidmeandits
in the crystal lattice are not occupied.
analogues which are present in solid dosage form or in a liquid
2.1.12 spindles—shorter than course needles, but more
form. They are not typically applicable to the analysis of
substantial cross-section.
phencyclidine and its analogues in biological samples.
3. Summary of the Technique
2. Terminology
3.1 Asmall sample of the material containing the suspected
2.1 Definitions:
phencyclidme or its analogues is dissolved in a dilute acid and
2.1.1 aggregation—the collecting of units or parts into a
the appropriate precipitating reagent is added. The crystals that
mass or whole.
are formed are observed and distinguished utilizing a light
2.1.2 birefringence—property of some crystals having more
microscope.
than one refractive index.This will result in interference colors
which are viewed through a polarized light microscope.
4. Significance and Use
2.1.3 habit—the external morphology of the crystal.
4.1 The technique produces a chemical-precipitation reac-
2.1.4 microdrop—a small drop of liquid that would fit on
tion between the phencyclidme or its analogues and the
theendofastandardsize,flattenedtoothpick.Theapproximate
precipitating reagent. The habit and the aggregation of the
volume of this drop would be 10 to 25 microliters.
crystals formed may be used to distinguish phencyclidine or its
2.1.5 nails—a skeleton of some kinds of triangles, elon-
analogues from other drugs.
gated, usually pointed with a short head usually thicker or
4.2 The technique can be utilized on phencyclidine or its
broader.
analogues present in either the salt or free base form.
2.1.6 needles (acicular)—long, thin crystals with pointed
4.3 Thetechniquedoesnotdistinguishbetweensaltandfree
ends.
base forms.
2.1.7 nuggets—irregularly formed grams without sharp
faces or edges.
5. Interferences
2.1.8 pliers—crystals resembling pliers, generally
5.1 Diluents/adulterants present in combination with phen-
X-shaped.
cyclidine or its analogues in the sample to be tested may result
in crystals that are distorted or otherwise rendered unidentifi-
able. In these instances, it will be necessary to separate the
This guide is under the jurisdiction of ASTM Committee E30 on Forensic
Sciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.
Current edition approved Jan. 10, 2001. Published March 2001.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E2125
phencyclidine or its analogues from the diluents/adulterants or 9.1.5.1 PCP (phencyclidine) produces purple razor blade
to use other testing methods to analyze for phencyclidine or its crystals. In high concentrations, the crystals resemble needles
analogues. impaling small spheres.
9.1.5.2 PCPy produces purple plier-shaped crystals with
6. Apparatus
embedded nuggets and irregular forms.
6.1 Standard light microscope capable of varying magnifi-
9.1.5.3 PCM produces unremarkable crystals.
cations including 1003 is needed for viewing the crystals.
9.1.5.4 TCP produces unremarkable crystals.
Polarized light attachment is not essential, but is desirable
9.1.6 If a dense cloud of precipitate is formed upon addition
because crystals resulting from the precipitation reaction are
of the precipitating agent, the crystals may not be readily
birefringent.
visible. It may be necessary to repeat the test reducing the
concentration of suspected phencyclidine or its analogue. This
7. Reagents and Materials
is done by either decreasing the sample size or increasing the
7.1 10 % v:v acetic acid.
volume of solvent.
7.2 10 % v:v hydrochloric acid.
9.2 Gold Bromide in diluted Perchloric and Acetic Acids
7.3 2 %w:vpotassiumpermanganatein0.5 %v:vphospho-
9.2.1 Place a small sample (a few particles of powder, less
ric acid.
than one (1) milligram (mg) or a small drop of liquid, allowed
7.4 Gold bromide (HAuBr ) in diluted perchtoric and acetic
to dry) of the suspected phencyclidine on a microscope slide.
acids [0.55 g HAuBr , 42 mL water, 37 mL concentrated
9.2.2 Dissolve the sample in a few microdrops of 10 %
perchloric acid, 21 mL glacial acetic acid].
acetic acid or 10 % hydrochloric acid.
7.5 Gold chloride (HAuCl ) in acetic and sulfuric acids
9.2.3 Add a few microdrops of gold bromide in diluted
[HAuCl in HOAc-4(1+1)H SO ; 2 g. HAuCl , 20 mL glacial
4 2 4 4
perchloric and acetic acids reagent to the edge of the acid
acetic acid, 40 mL concentrated sulfuric acid, 40 mL water].
solution on the microscope slide. Cover with a coverslip.
7.6 Authentic phencyclidine [PCP; 1-(1-
9.2.4 Observe the formation of crystal using a properly
phenylcyclohexyl)piperidine].
aligned and adjusted light microscope. The observation can be
7.7 Authentic pyrrolidine analogue of phencyclidine [PCPy,
done between crossed polars, if desired. If crossed polars are
PHP, 1-(1-phenylcyclohexyl)pyrrolidine].
used, care should be used to orient the polarizer in the
7.8 Authentic morpholine analogue of phencyclidine [PCM,
east-west direction and the analyzer in the north-south direc-
1-(1-phenylcyclohexyl)morpholine].
tion, verified by a black background.
7.9 Authentic thiophene analogue of phencyclidine [TCP;
9.2.5 The crystal formation will depend on the drug present,
1-[l-(2thienyl)cyclohexyl]piperidine].
if any. The formation that can be expected for phencyclidine
and its analogues are as follows:
8. Calibration and Standardization
9.2.5.1 PCP (phencyclidine) produces red-gold colore
...