Simultaneous gas chromatographic determination of methamphetamine, amphetamine and their p-hydroxylated metabolites in plasma and urine.
We report a method for the simultaneous determination of methamphetamine, amphetamine and their hydroxylated metabolites in plasma and urine samples using a GC-NPD system. The analytical procedures are: (1) adjust the sample to pH 11.5 with bicarbonate buffer, saturate with NaCl and extract with acetate; (2) back-extract the amines in the ethyl acetate fraction with 0.1 M HCl; (3) adjust the pH of the acid fraction to 11.5 and follow by extraction in ethyl acetate; (4) reduce the volume of ethyl acetate under nitrogen and derivatize the concentrate with trifluoroacetic anhydride or heptafluorobutyric anhydride before the GC analysis. The derivatives were separated on a GC-NPD system equipped with a HP-5 column of 25 m x 0.32 m I.D. and a 0.52 micron film of 5% phenylmethylsilicone. The detection limit (taking a signal-to-noise ratio of 2) of heptafluorobutyl derivatives of methamphetamine and its metabolites in plasma and the trifluoroacetyl derivatives in urine was 1 ng/ml (22 pg on column). The limit of quantitation of the heptafluorobutyl derivatives in the plasma was 1 ng/ml (22 pg on column), and that of the trifluoroacetyl derivatives in urine was 20 ng/ml (73 pg on column). The between-day variation was from 0.9 to 17.4% and within-day variation from 0.9 to 8.3%. This method was used successfully in the quantitative determination of methamphetamine and its p-hydroxylated metabolites in the plasma and urine of human subjects.
Cheung
S
S
Biobehavioral Research Department, Addiction Research Foundation of Ontario, Toronto, Canada.
Nolte
H
H
Otton
S V
SV
Tyndale
R F
RF
Wu
P H
PH
Sellers
E M
EM
D000661:Amphetamine / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D000697:Central Nervous System Stimulants / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D002849:Chromatography, Gas; D006801:Humans; D006900:Hydroxylation; D008694:Methamphetamine / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000697:Central Nervous System Stimulants; D008694:Methamphetamine; D000661:Amphetamine