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.
Peters
Frank T
FT
Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, D-66421 Homburg (Saar), Germany.
Kraemer
Thomas
T
Maurer
Hans H
HH
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