Stereoselective screening for and confirmation of urinary enantiomers of amphetamine, methamphetamine, designer drugs, methadone and selected metabolites by capillary electrophoresis
A. Ramseier et al., Stereoselective screening for and confirmation of urinary enantiomers of amphetamine, methamphetamine, designer drugs, methadone and selected metabolites by capillary electrophoresis, ELECTROPHOR, 20(13), 1999, pp. 2726-2738
Data presented in this paper demonstrate that a competitive binding, electr
okinetic capillary-based immunoassay previously used for screening of urina
ry amphetamine and analogs cannot be employed to distinguish between the en
antiomers of amphetamine and methamphetamine. However, capillary zone elect
rophoresis with a pH 2.5 buffer containing (2-hydroxypropyl)-beta-cyclodext
rin as chiral selector is shown to permit the enantioselective analysis of
urinary extracts containing methamphetamine, amphetamine, 3,4-methylenediox
ymethamphetamine (Ecstasy) and other designer drugs, and methadone together
with its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidi
ne. In that approach, enantiomer identification is based upon comparison of
extracted polychrome UV absorption data and electropherograms obtained by
rerunning of spiked extracts with spectra and electropherograms monitored a
fter extraction of fortified blank urine. The suitability of the described
chiral electrokinetic capillary method for drug screening and confirmation
is demonstrated via analysis of unhydrolyzed quality control urines contain
ing a variety of drugs of abuse. Furthermore, in a urine of a patient under
selegiline pharmacotherapy, the presence of the R-(-)-enantiomers of metha
mphetamine and amphetamine could be unambiguously identified. Direct intake
of an R-enantiomer or ingestion of drugs that metabolize to the R-enantiom
ers can be distinguished from the intake of S-(+)-enantiomers (drug abuse)
or prescribed drugs that metabolize to the S-enantiomers of methamphetamine
and amphetamine. The described approach is simple, reproducible, inexpensi
ve and reliable (free of interferences of other major basic drugs that are
frequently found in toxicological urines) and could thus be used for screen
ing for and confirmation of urinary enantiomers in a routine laboratory.