Analysis, stability and distribution of pharmaceuticals and drugs of abuse over a period of one year in formalin-fixed liver and formalin solutions

Abstract

The aim of the present study was to develop, validate and apply an analytical method for the determination of a large number (84 target analytes) of drugs of abuse and pharmaceuticals in formalin- fixed human liver and formalin solution to investigate their fate within a period of one year (1, 3, 6 and 12 months). A UPLC-MS/MS method was developed, on a reversed-phase column (C18) and a gradient of MeOH over H2O with a 13 minutes run for 84 drugs and pharmaceuticals. MRM mode was applied for the detection and quantification of all 84 analytes of interest by monitoring selected transitions. The target compounds comprise opiates, cocaine, cannabinoids, amphetamines, benzodiazepines, antipsychotics, antidepressants and NPSs. Sample pretreatment process was also studied. The results showed that a number of the detected compounds in the first month was significantly lower than the compounds found in fresh tissues. The effect of formalin was catalytic, and few substances could be detected. Specifically, out of the 86 positive detections of the monitored drugs and pharmaceuticals substances in the fresh tissues (in which 25 different substances were found), only 32 (37%) remained detectable 3 months after, 20 (23%) 6 months after and 15 (17%) 12 months after. In the present study a UHPLC-MS/MS method for determination of 84 drugs in fixed-liver tissues and formalin solutions has been developed, validated and applied to 14 forensic cases. Totally 25 drugs were found in the fresh liver tissue in 16 cases and their detectability and stability during 12 months in respective fixed-liver tissues and formalin solutions were studied. Useful findings were found for forensic toxicologists to properly evaluate the results of toxicological analysis in cases, where the only available samples to be examined are fixed-liver tissues and formalin solutions.