Application of modified QuEChERS method to liver samples for forensic toxicological analysis

In forensic toxicological analysis, liver is commonly used as an alternative biological specimen in cases in which blood and urine cannot be obtained. Liver samples are generally purified by a solid-phase extraction (SPE) technique after homogenization. The homogenizer probe cleaning process is laborious and has a risk of cross-contamination, and the SPE technique itself is tedious and time consuming. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method is widely acknowledged in some fields, such as food analysis, as a simple, fast, and reliable method. We previously developed a modified QuEChERS method for forensic toxicological analysis in human whole blood and urine. In this study, we applied this method to liver samples from forensic cases and successfully detected not only targeted drugs (i.e., benzodiazepines, zopiclone, and zolpidem) but also various types of drugs. This method has no risk of cross-contamination because homogenization of the liver and extraction of the drugs are simultaneously performed in a disposable plastic tube. In addition, the total process time is approximately 5 min. We recommend the modified QuEChERS method for extraction of drugs from both fluid and solid samples, such as liver, in forensic cases.