Problems of Forensic Sciences 2007 Vol. 72 (LXXII) 416-432
TOXICOLOGICAL ANALYSIS OF VALPROIC ACID IN BLOOD BY FLUORESCENCE POLARISATION IMMUNOASSAY (FPIA) IN COMPARISON TO GAS CHROMATOGRAPHY COUPLED WITH MASS SPECTROMETRY (GC-MS)
Jolanta WILIMOWSKA1, Małgorzata KŁYS2, Sebastian ROJEK2, Bartosz JENNER1, Krzysztof CISZOWSKI3
1Laboratory of Analytical Toxicology and Monitored Therapy, Collegium Medicum of Jagiellonian University, Krakow, Poland
2Chair and Department of Forensic Medicine, Collegium Medicum of Jagiellonian University, Krakow, Poland
3Toxicology Clinic, Collegium Medicum of Jagiellonian University, Krakow, Poland
Streszczenie
The report presents the results of a comparative study of valproic acid assays performed using the fluorescence polarisation immunoassay (FPIA) technique on the Abbott Axsym System and a developed analytical procedure based on gas chromatography – electron ionisation mass spectrometry (GC-MS). A specific method (GC-MS) for the quantitative determination of valproic acid in human plasma has been validated and presented in this paper. Valproic acid was extracted from acidified plasma by ethyl acetate and converted to its trimethylsilyl derivative, giving ions at m/z 201, which were used in quantitative analysis. Material for analysis included 41 samples of blood collected from six poisoned patients who took a toxic dose of valproic acid with the aim of committing suicide. They had a history of epilepsy or mood disturbances and were treated with valproic acid alone or in combination with psychotropic drugs. A comparison of the FPIA results with those obtained by a reference method (GC-MS) showed no statistical difference. The correlation coefficient was 0.9814. The good correlation between the two methods, the simplicity and short run time of the FPIA could make it useful in clinical practice. The reference GC-MS method may be used in a study of metabolic profiling of valproic acid.
Słowa kluczowe
Valproic acid; FPIA; GC-MS; Human serum.