Problems of Forensic Sciences 2009 Vol. 79 (LXXIX) 294-302
DETERMINATION OF KETONE BODIES IN POST-MORTEM BLOOD AND URINE BY GAS CHROMATOGRAPHY-POSITIVE-ION CHEMICAL IONISATION-MASS SPECTROMETRY
Krzysztof BAŃKA, Grzegorz BUSZEWICZ, Roman MĄDRO
Chair and Department of Forensic Medicine, Medical University, Lublin, Poland
Streszczenie
Under physiological conditions, the levels of ketone bodies in blood are low. Their production increases in significant insulin deficiency and alcohol abuse, and this can lead to ketoacidosis. Hence, the determination of main ketone bodies, that is b-hydroxybutyric acid (b-HBA) and acetoacetic acid (Ac-Ac), may be useful for diagnosis of sudden deaths. A simple and quick method of b-HBA and Ac-Ac determination in post-mortem material (blood and urine) using gas chromatography – chemical ionisation mass spectrometry was developed. The samples were extracted with acetonitrile. BSTFA + 1% TMCS was used for derivatisation. The mass detector was operated in positive chemical ionisation mode; monitoring of selected ions: m/z 233 (b-HBA), m/z 231 (Ac-Ac) and m/z 239 (GHB-D6 used as an internal standard) was applied for quantitative analysis. The use of chemical ionisation enabled reduction of the influence of the biological matrix (blood and urine), even when the decomposition process had started. Full validation of the method demonstrated its specificity, high linearity (r2 > 0.99), extraction yields suitable for forensic toxicological analysis (77–97%), accuracy and precision.
Słowa kluczowe
Ketone bodies; Post-mortem blood and urine; Validation; GC-PCI-MS.