Development and validation of a rapid GC–MS method for seized drug screening

Abstract

Controlled substances are one of the most commonly analyzed types of evidence in forensic laboratories. Persistent, high levels of case submissions in recent years have created a need for rapid screening techniques to decrease case backlogs and expedite confirmatory analyses. The most utilized technique for the analysis of seized drugs is gas chromatography mass spectrometry (GC-MS). While this approach typically takes tens of minutes, advances in the technique have enabled approximately 1 min run times with a short column and a rapid (10’s °C/s) temperature program. These advances were used in this work to develop and validate a rapid GC-MS method for screening seized drug samples. Method validation was completed to determine retention time repeatability and reproducibility, limits of detection, identification accuracy, selectivity, and carryover. Validation results showed the utility of this method for accurate and precise qualitative analyses for the screening of seized drugs across seven different drug classes. The optimized method was then applied to 15 real and mock case samples from the Maryland State Police Forensic Sciences Division. Controlled substances, cutting agents, and other diluents were identified from these samples using acceptance criteria of retention time and mass spectral comparisons currently used in casework. Using rapid GC-MS methods in casework could enable faster and more reliable presumptive testing results for the analysis of seized drug exhibits.