methods for impurity profiling of heroin and cocaine - United Nations ...

Methods for impurity profiling 27
products obtained from the action of acetic anhydride on ring-bound tertiary
amines [37, 40-47]. Additionally, such compounds as N-acetylnorlaudanosine and
the N-acetylated papaverubine isomers arise as simple acetylation addition products
of alkaloids that are naturally present in opium as secondary amines.
Method B1: GC method, without derivatization
Source: L. Strömberg and others, “Heroin impurity profiling: a harmonization study
for retrospective comparisons”, Forensic Science International, vol. 114, No. 2 (2000),
pp. 67-88.
Operating conditions:
Detector: FID at 30 ml/min hydrogen, air at 400 ml/min
Column: HP Ultra-2 or equivalent, 25 m x 0.20 mm x 0.11 µm
Carrier gas: Helium at about 0.6 ml/min
Injection
technique: 1 µl; split, 25:1
Make-up gas: Helium at 30 ml/min.
Temperatures: Injector: 300° C
Detector: 330° C
Oven: 160° C to 320° C at 6° C/min, hold for 6 min
Internal standard: Tetracontane at 10 mg/l in toluene
Sample preparation: Place an amount of sample equivalent to 15 mg of pure heroin
(equivalent to base) into a glass tube. Add 5.0 ml of 0.5N sulphuric acid to dissolve
the sample; then add 5.0 ml of internal standard solution. Mix thoroughly and then
centrifuge to separate the phases. Remove 3.2 ml of the internal standard solution and
evaporate to dryness. Add 200 µl of toluene and sonicate.
Reference chromatogram: See annex III, figure IV and table 3. The 16 selected reference
peaks marked in the figure and presented in annex III, table 3, are used for
retrospective comparisons with a computerized data retrieval system. The experience
gained during a study of the national forensic science laboratories of Germany, the
Netherlands and Sweden is reported in reference [48].
Rationale for use: No derivatization,* relatively simple sample preparation and good
separations for nearly all components. Will not detect sugars and sensitivity probably
not sufficient for highly refined heroin samples.
Outcome: Sample comparisons for discrimination and evaluation of samples for caseto-case
evidential purposes (linkage determinations). Provides additional information
required to confirm links between samples, that is, the method should be used in conjunction
with a major component analysis.
*See the subsection entitled “Hydrolysis of heroin” for possible problems related to the use
of methods that do not employ derivatization.