Page 95 - Advances in Forensic Applications of Mass Spectrometry - Jehuda Yinon

1522_C02.fm Page 82 Wednesday, November 12, 2003 9:36 AM

in saliva. Collected saliva (50 ml) was diluted with a 200 ml methanolic
solution of an internal standard mixture (deuterated analogs) and centri-
fuged. Supernatant was subjected to HPLC in an ACN–ammonium acetate
mobile phase on a C18 column. The drugs were detected using transitions
of protonated quasi-molecular ions in optimized conditions. The LOQs were
1 to 5 mg/l. This method was used further for determination of designer
amphetamines in oral fluid, sweat wipe, and plasma after controlled admin-
istration of MDMA and in real life conditions (after ingestion of Ecstasy
tablets at a party). Toxicokinetic data were gathered, indicating very high
intra- and interindividual variability of saliva results. In sweat, very low
concentrations of MDMA were detected in the first 5 h after drug intake. 81
Stanaszek et al. applied LC/APCI/MS for determination of amphetamines,
82
as well as other drugs of abuse, in hair.

2.3.3 Cocaine
Cocaine may be administered in different ways — by smoking, intranasal
(“snorting”), oral, or intravenous route. This drug is converted in the human
body into a multitude of active and nonactive metabolites, mostly of high
polarity. These metabolites are amenable to GC/MS analysis only after
derivatization. 83

2.3.3.1 Analysis of Biological Fluids
The advent of LC/MS brought substantial progress in liquid chromatographic
detection of cocaine metabolites, which may be found without any derivati-
zation with this technique. Sosnoff et al. detected BZE in dried blood spots
84
with tandem LC/MS. A LOD of 2 mg/l was achieved from a 12-ml sample.
This technique was used for epidemiological screening in a study involving
85
newborns. Singh et al. applied acetonitrile precipitation for isolation of
cocaine and metabolites from plasma. The drugs were determined with
LC/APCI/MS/MS. The LOQ was 2 mg/l for cocaine, benzoylecgonine, and
norcocaine, and 5 mg/l for ecgonine methyl ester. The procedure has been
applied for pharmacokinetic study in rats. In a study of Jeanville et al. a fast-
gradient ESI/LC/MS/MS was applied for automated urinalysis. Urine samples
were only filtered and transferred into a 96-well plate before injection. Total
analysis time was 2 min. However, the issue of possible matrix interference
87
was not addressed. In the next paper of Jeanville et al., centrifuged urine
86
samples were injected into LC/MS/MS system equipped with an on-line
extraction unit. Total analysis time was below 4 min. The LODs for EME,
BZE, and cocaine were 0.5, 2, and 0.5 mg/l, respectively. The same research
group studied the applicability of LC/ESI/qTOF for direct determination of

© 2004 by CRC Press LLC