Problems of Forensic Sciences 2008 Vol. 73 (LXXIII) 44-52
CORTISOL, CORTISONE AND CORTICOSTERONE DETERMINATION IN BIOLOGICAL MATERIALS BY LIQUID CHROMATOGRAPHY MASS SPECTROMETRY
Krzysztof BAŃKA, Grzegorz BUSZEWICZ, Grzegorz TERESIŃSKI, Roman MĄDRO
Chair and Department of Forensic Medicine, Medical University, Lublin, Poland
Streszczenie
A liquid chromatography mass spectrometry (LC-MS) assay was developed and optimised for the determination of cortisol, cortisone and corticosterone. In order to separate analytes from the biological matrix, the liquid-liquid extraction method was applied. Post-mortem blood was extracted with dichloromethane in alkaline medium (pH 6.5). The mass spectrometer (MS) was operated in atmospheric pressure chemical ionisation (APCI) mode. Quantitative analysis was carried out in the selected ion monitoring mode (SIM). Quantitative analysis was carried out on the basis of analytical signals obtained for positive pseudomolecular ions of the determined substances (m/z – 363 for cortisol, m/z – 361 for cortisone, m/z – 347 for corticosterone) and dexamethasone (m/z – 393), which was used as an internal standard. Method validation was performed and the limit of detection was 0.5 ng/ml for cortisol and cortisone, and for corticosterone it was 1.0 ng/ml. Linearity was obtained for all of the three mentioned glucocorticosteroids in the range from 1 to 500 ng/ml. We also determined precision and extraction yield. It was ascertained that the method both guarantees a high extraction yield and enables the determination of all of the three mentioned glucocorticosteroids in one analytical procedure. The method proved to be highly sensitive and precise, and to have a wide range of linearity of detection. It was also confirmed that it enables the determination of glucocorticosteroids in blood samples collected from a cadaver.
Słowa kluczowe
Glucocorticosteroids; Validation methods; Post-mortem blood; LC-APCI-MS.