Drug testing in blood: validated negative-ion chemical ionization gas chromatographic-mass spectrometric assay for determination of amphetamine and methamphetamine enantiomers and its application to toxicology cases.
BACKGROUND
Enantioselective analysis of amphetamine (AM) or methamphetamine (MA) in urine is already a well-established tool for differentiation of illicit from therapeutic ingestion of AM or MA derivatives. However, because of the increasing importance of plasma or serum in analytical toxicology, a method for enantioselective analysis of AM and MA in these matrices is needed.


METHODS
AM and/or MA were extracted from 0.2 mL of blood plasma or serum by mixed-mode solid-phase extraction. After derivatization with S-(-)-heptafluorobutyrylprolyl chloride, the resulting diastereomers were separated by gas chromatography on a HP-5MS column during a 15-min program and detected by mass spectrometry in the negative-ion chemical ionization mode (NICI-GC-MS). The method was fully validated and applied to >50 samples from authentic toxicology cases.


RESULTS
The derivatized AM and MA enantiomers were well separated and sensitively detected. The method was linear from 5 to 250 micro g/L per enantiomer with analytical recoveries, accuracy, and within- and between-run precision well within required limits. Extraction yields were 88.9-98.6%. Implications of concentrations and enantiomeric composition of AM and MA in the authentic samples were considered.


CONCLUSIONS
This sensitive, reliable, rapid NICI-GC-MS assay is suitable for enantioselective determination of AM and MA in blood plasma or serum samples.
Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, D-66421 Homburg (Saar), Germany.
Frank T
FT
Peters
Thomas
T
Kraemer
Hans H
HH
Maurer
D000661:Amphetamine / Q000097:blood* / Q000737:chemistry; D001800:Blood Specimen Collection; D004355:Drug Stability; D005466:Fluorocarbons / Q000138:chemical synthesis; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007202:Indicators and Reagents; D008694:Methamphetamine / Q000097:blood* / Q000737:chemistry; D011392:Proline / Q000031:analogs & derivatives / Q000138:chemical synthesis; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D015813:Substance Abuse Detection / Q000379:methods*
D005466:Fluorocarbons; D007202:Indicators and Reagents; D008694:Methamphetamine; C058908:N-heptafluorobutyrylproline; D011392:Proline; D000661:Amphetamine