Page 37 - Advances in Forensic Applications of Mass Spectrometry - Jehuda Yinon

1522_C01.fm Page 24 Tuesday, December 2, 2003 10:05 AM

Papers on the detection time of drugs of abuse in urine have recently been
reviewed. 121 Three typical STA procedures have been published for urinalysis:
one for the detection of doping-relevant stimulants, beta-blockers, beta-
agonists, and narcotics after enzymatic hydrolysis, SPE, and combined TMS
2
and TFA derivatization; one for the detection of most of the basic and
neutral drugs in urine after acid hydrolysis and LLE and AC, 1,57,172 recently
modified and improved for newer drugs of interest; 58,61,62,126,139,166 and one
for acidic drugs, poisons, and/or their metabolites in urine after extractive
methylation. 65–69

1.4.2.1 General Screening Procedure for Drug Classes
Relevant in Doping after Enzymatic Hydrolysis, SPE,
and Combined TMS and TFA Derivatization
A screening procedure was published for the detection of doping relevant
stimulants, beta-blockers, beta-agonists, and narcotics after enzymatic
2
hydrolysis, SPE, and combined TMS and TFA derivatization. The time-
consuming enzymatic cleavage of conjugates is acceptable for doping analysis
since results do not have to be available as fast as in emergency toxicology.
The authors did not focus their procedure on the detection of the metabolites,
even if they could be detected in most cases for a longer time and more
sensitively than their parent compounds. The chemical properties of the
analytes allowed use of SPE with acceptable recoveries. However, the large
differences from batch to batch should be kept in mind. The combined
70
TMS and TFA derivatization provided very good GC properties, but
underivatized samples cannot be analyzed on the same GC/MS apparatus
without changing the column.
This screening procedure, which is limited to some doping-relevant
drugs, is also based on full scan GC/MS and mass chromatography for doc-
umentation of the absence of the corresponding drug. Such exclusion pro-
cedure is suitable for doping analysis since the prevalence for positives is low
in contrast to clinical toxicology where the prevalence is high and where
many more drugs must be detected or excluded.

1.4.2.2 General Screening for Most of the Basic and Neutral
Drug Classes in Urine after Acid Hydrolysis, LLE,
and AC
A screening method for detection of most of the basic and neutral drugs in
urine after acid hydrolysis, LLE, and AC, has been developed, improved upon,
and extended during the last few years. Cleavage of conjugates was necessary
before extraction since part of the drugs and/or their metabolites were
excreted into urine as conjugates. For studies on toxicological detection, rapid
acid hydrolysis was performed to save time, which is relevant, e.g., in emer-

© 2004 by CRC Press LLC