A Paradigm Shift in Forensic Toxicology Screening: The Development and Validation of Two Automated Sample Preparation Techniques for the Comprehensive Screening of Biological Matrices Using High Resol

The Virginia Department of Forensic Science (DFS) will develop and validate two automated sample preparation techniques for a robust screening method using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-qTOF) that will promote efficiency and exceed the validation guidelines set forth by the Scientific Working Group for Forensic Toxicology (SWGTOX). Conventional screening methods include multiple analytical and instrumental methods in order to achieve comprehensive screening results for an individual sample. These methods include a two-tiered system including classification of drugs using enzyme immunoassay based techniques with subsequent extraction and analysis using gas chromatography mass spectrometry (GC-MS) for further screening and identification of drugs. The utilization of fully automated sample preparation in tandem with LC-qTOF has the potential to significantly impact the field of forensic toxicology by reducing the need for multiple screening and confirmation methodologies, removing human interactions during sample preparation, and promoting the inherent greater specificity and retrospective analysis capabilities of high resolution mass spectrometry. Limited literature exists for automated sample preparation techniques and comprehensive screening using LC-qTOF for both antemortem and postmortem biological matrices. Within this project, tubular (large scale) and 96-well plate fully automated solid phase extraction procedures will be developed and evaluated. Existing manual solid phase extraction procedures for LC-qTOF analysis of biological matrices will be utilized for development of the automated processes. Establishing an automated comprehensive qualitative screen using LC-qTOF has the potential to also significantly impact laboratory efficiency. Increased efficiency will directly impact the criminal justice system for cases such as driving under the influence of alcohol/drugs (DUI/DUID) and death investigation by reducing turnaround times for case completion and allow for more comprehensive screening. A three month tandem study of current screening procedures at DFS including administrative stop testing limits, enzyme immunoassay, and GC-MS screen with the existing manual solid phase extraction for the LC-qTOF method and the fully automated sample preparation LC-qTOF methods will be conducted to thoroughly compare and contrast the processes. The collective results of the fully automated comprehensive screen compared to existing multi-step analytical techniques has the potential to positively significantly impact the forensic toxicology community by enhancing the scope of testing while decreasing overall turnaround times as well as enable laboratories to make data driven decisions concerning methodology choices.
Note: This project contains a research and/or development component, as defined in applicable law, and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14).
CA/NCF