Examination of Firearms Review: 2007 to 2010 - Interpol

cut-off of 30 pg/mg scalp hair (measured in the 0-3 cm proximal segment) to
differentiate chronic excessive alcohol consumption [431]. Black and white
patches of fur from LE rats were taken before and after daily intraperitoneal
injection of ethanol to study the effect of hair pigmentation in fatty acid ethyl
ester (FAEE) incorporation [432]. The FAEE profiles were similar between
black and white hair, and so hair pigmentation was concluded not to affect
FAEE incorporation into hair. To assess the influence of ethanol contamination,
an in vitro experiment was performed, leaving hair in an atmosphere saturated
with ethanol vapor for 15 days [433]. Under this stressed experimental
condition, the spontaneous production of FAEEs was demonstrated by
analyzing hair daily with an SPME-GC-MS technique, and a constant increase
of ethyl myristate, palmitate, and stearate was observed. The problem of hair
contamination that can occur, for example, with ethanol-containing cosmetics
should be taken into account in interpretation of results.
GC-MS and LC-MS(MS) are commonly employed in hair drug analysis, but
other analytical techniques are also used. Using 100 mg of hair sample and
nalorphine as internal standard, a capillary zone electrophoresis mass
spectrometry (CZE-MS) method was developed for analysis of common drugs
of abuse and their metabolites [265]. The LODs were lower than the 0.1 ng/mg
cut-offs commonly adopted in hair analysis. MALDI-MS was used for the rapid
detection of cocaine, benzoylecgonine, and cocaethylene in hair. The hair
samples were required to be incubated in methanol/trifluoroacetic acid for 15
min at 45 o C prior to MALDI-MS analysis [434]. Surface-activated chemical
ionization (SACI) was employed for the analysis of cocaine and its metabolite,
benzoylecgonine, extracted from hair. Following decontamination and acid
hydrolysis, the sample solutions were diluted (1:10) and directly analyzed by
LC/SACI-MS [435]. The LODs and LOQs were 0.003 ng/mg and 0.01 ng/mg,
respectively, for cocaine and 0.02 ng/mg and 0.04 ng/mg for benzoylecgonine.
Detection of drugs of abuse in hair is also important for monitoring compliance
with drug abstinence. Therefore, understanding the mechanisms and timeline
of drug disappearance from hair is critical for clinical and forensic application of
hair testing. The kinetics of disappearance of cocaine and its metabolite,
benzoylecgonine, from hair after discontinuation of drug use was evaluated
using 137 subjects [436]. The results revealed that the median half-life of both
cocaine and benzoylecgonine was 1.5 months and approximately 3-4 months,
were required to “pass” hair testing when the analysis was performed in the
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