|SOFT - TIAFT 1998||Poster Session 4||Friday October 9, 1998|
DETERMINATION OF FLUNITRAZEPAM AND ITS METABOLITES IN BLOOD BY MEANS OF HIGH PERFORMANCE LIQUID CHROMATOGRAPHY-ATMOSPHERIC PRESSURE CHEMICAL IONIZATION MASS SPECTROMETRY|
Maciej J.Bogusz, Rolf-Dieter Maier, Klaus-Dieter Krüger, Wiebke Früchtnicht
Institute of Forensic Medicine, Aachen University of Technology, 52057 Aachen, Germany
|A selective assay of flunitrazepam (F) and its metabolites: 7-aminoflunitrazepam (7-AF), N-desmethylflunitrazepam (N-DF) and 3-hydroxyflunitrazepam (3-OHF) with liquid chromatography atmospheric pressure chemical ionization (LC-APCI-MS, positive ions) was developed. The drugs were isolated from serum, blood or urine by solid phase extraction. F-d3 and 7AF-d3 were used as internal standards. The drugs were separated on an ODS column in acetonitrile-50 mM ammonium formate buffer, pH 3.0 (45:55). After analysis of mass spectra taken in full scan mode, a selected-ion monitoring detection was applied with following ions: m/z 284 (7-AF and F), 287 (7AF-d3 and F-d3), 314 (F), 300 (N-DF and 3-OHF), 317 (F-d3), 330 (3-OHF).
The limits of detection (µg/l) were: 0.2 for F and 7-AF, 1 for N-DF and 3-OHF. The method was linear in range 1-500 µg/l; the recoveries ranged from 92 to 99%. The method was applied for determination of F and metabolites in clinical and forensic samples. In 8 positive forensic samples, blood concentrations (µg/l) of F ranged from 4 to 48, concentrations of 7-AF 4 to 48. In 4 cases N-DF was detected (2-31 µg/l) and in 2 cases 3-OHF (10-12 µg/l). LC-APCI-MS seems to be a method of choice for these compounds.