Page 96 - Advances in Forensic Applications of Mass Spectrometry - Jehuda Yinon

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cocaine and ecgonine methyl ester in rat plasma. Similar performance as
for the triple-quadrupole instrument was observed.
Skopp et al. carried out the study on the stability of cocaine and metab-
olites (benzoylecgonine, ecgonine methyl ester, and ecgonine) at different
temperatures using LC/ESI/MS/MS. 89,90 The drugs were isolated from human
plasma by SPE and separated on a narrow-bore C8 column. For each com-
pound, one product ion originating from the protonated quasi-molecular
ion was monitored. Only ecgonine appeared to be stable at room tempera-
ture. The conversion of cocaine to final metabolite ecgonine was stoichio-
metric. A validated LC/APCI/MS/MS procedure for cocaine and
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benzoylecgonine in human plasma was published by Lin et al. The transi-
tions m/z 304 Æ182 and 290 Æ 168 were monitored for cocaine and ben-
zoylecgonine, respectively. The LOQ was 2.5 mg/l for both compounds.
Table 2.2 presents liquid chromatographic methods published recently
for amphetamines and cocaine analysis.

2.3.3.2 Analysis of Alternative Samples
Clauwaert et al. determined cocaine, benzoylecgonine, and cocaethylene in
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hair samples. Hair samples were hydrolyzed with HCL and extracted with
Confirm HCX cartridges. The extracts were subjected to LC/ESI/MS and
HPLC with fluorescence detection. The procedure was applied in 29 forensic
drug overdose cases and close agreement for results obtained from both
detection methods was observed.

2.3.3.3 Prenatal Exposure to Cocaine
The analysis of cocaine and its metabolites in meconium, placenta, or amni-
otic fluid may give a valuable indication of prenatal exposure to this drug.
Xia et al. established a LC/ESI/MS/MS method for the determination of
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cocaine and 12 metabolites in meconium. The method was tested on 22 drug-
positive meconium samples. In 21 cases the presence of at least 8 metabolites
was stated. Ecgonine appeared to be the most sensitive marker of cocaine
exposure. The same method was applied in the study on distribution of
cocaine and metabolites in blood, amniotic fluid, placental, and fetal tissues
of pregnant rats after intravenous cocaine administration. 94

2.3.4 Cannabis

2.3.4.1 Analysis of Street Drugs
Particle beam ionization (PBI) LC/MS was applied for separation and iden-
tification of cannabinoids (THC, cannabinol, cannabidiol, acidic cannab-
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inoids) in hashish samples. Quantitative data were not given. Since PBI
interface has been largely abandoned, this paper is rather of historical value.

© 2004 by CRC Press LLC