The Screening of Forensic Blood, Urine, and Tissue Specimens for Xenobiotics Using Ion-Trap Liquid Chromatography-Tandem Mass Spectrometry

Abstract

During the investigation of aviation accidents, postmortem specimens from accident victims including blood, urine, and tissue are submitted to the Federal Aviation Administration's Civil Aerospace Medical Institute (CAMI) for toxicological analysis. The first, and perhaps most important, step in the analysis process is the initial screening of biological specimens for illicit, medically prescribed, and over-the-counter compounds that may be present and potentially be a cause and/or factor in the accident. Currently, our general unknown screening (GUS) procedure involves, in part, both gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC) with both diode-array detection (DAD) and fluorescence detection. Both GC and LC techniques have inherent limitations that prevent the detection of certain types of compounds. The decreased specificity and sensitivity of LC-DAD has been an impediment to the existing GUS procedure. Therefore, our laboratory set out to develop and validate an LC-MS-MS procedure that is superior to LC-DAD. The limits of detection of 359 forensically important xenobiotics have been established following solid-phase extraction from whole blood and analysis by LC-MS-MS. Although whole blood was used as the matrix during instrument validation, the method has been successfully applied to both forensic urine and tissue specimens as well.