Examination of Firearms Review: 2007 to 2010 - Interpol

MDA, respectively, at the 25-ng/patch threshold proposed by SAMHSA.
Variability in sweat excretion suggests that results should be interpreted
qualitatively rather than quantitatively. In a similar study for MA, 8 participants
received four 10-mg oral doses (low dose) of sustained-release S-(+)-MA HCl
(d-MA HCl) within 1 week, and 5 of them also received four 20-mg (high) doses
3 weeks later. MA was measurable in sweat within 2 h of dosing. 92.9% (low
dose) and 62.5% (high dose) of weekly sweat patches were positive, with
median concentrations of MA being 63.0 and 307 ng/patch, respectively [449].
THC excretion in 11 daily cannabis users after cessation of drug use was
evaluated. Sweat patches worn the first week of continuously monitored
abstinence had THC above the proposed cutoff concentration of 1 ng
THC/patch, with mean THC concentrations being 3.85±0.86 ng/patch. Daily
and weekly sweat patches from seven subjects who were administered oral
doses of up to 14.8 mg THC/day for five consecutive days were also tested,
but no daily or weekly patches had THC above the LOQ (i.e., 0.4 ng
THC/patch) [ 450 ]. Simultaneously quantification of methadone, heroin,
cocaine and metabolites in sweat was developed by extracting drugs from
sweat patches with sodium acetate buffer, followed by SPE and quantification
by GC/MS, with LOQs of 5-10 ng/patch [451].
3.4.4 Meconium
Meconium is a newborn’s first stool. It is formed over the last trimester of
pregnancy, and thus can represent exposure to drugs over a 16-20 week
prepartum and provide a crucial indication of neonatal exposure or maternal
drug use. Simultaneous quantification of 20 drugs in meconium, including
cocaine, amphetamine, opiate, and nicotine analytes, by LC-MS/MS was
developed and applied to document drug-exposed neonates [230]. In a study
of amphetamines and related analytes in meconium, it was found for the first
time that para-hydroxymethamphetamine (pOHMAMP), norephedrine
(NOREPH), and 4-hydroxy-3-methoxymethamphetamine were identified in
meconium from a MA-exposed neonate [452]. However, MA exposure is poorly
reflected in neonatal meconium; often, maternal self-reported MA use is not
corroborated by positive results in amphetamines immunoassays of meconium,
and even if the initial test results are positive, they frequently are not confirmed
for MA or amphetamine (AMP) by chromatographic analysis.
Immunoassay-positive and -negative meconium samples were subjected to
LC-MS/MS to re-analyse for MA metabolites pOHMAMP,
p-hydroxyamphetamine (pOHAMP), and NOREPH. It was found that
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