Combining LC-MS/MS Product-Ion Scan Technology with GC-MS Analysis to Identify Drugs and Poisons in Postmortem Fluidsand Tissues

Miami-Dade County Medical Examiner Department Toxicology Laboratory (MDME) maintains a scope of testing which can identify a broad spectrum of drugs/poisons in order to successfully aid in the determination of cause and manner of death. Using the most effective analytical techniques for screening a broad range of drugs and poisons is today’s most significant challenge for forensic toxicology laboratories, becoming more evident since 2010 due to the growth of novel synthesized drugs or “new psychoactive substances” (NPS) flooding the local community. Designing adequate screening protocols that are comprehensive and accurate in drug identification while controlling operating costs and turnaround time has been a strong initiative for most laboratories.

MDME has successfully conducted preliminary studies that evaluate the effectiveness of fast-scanning liquid chromatography-tandem mass spectrometry (LC/MS/MS), creating a detailed merged-product ion scan spectra with library search capabilities to identify substances more accurately. The project’s intent is to establish its effectiveness in replacing more traditional immunoassay testing procedures that are costly, of limited scope, non-specific, and can only provide presumptive results. The goal is to develop a superior screening protocol that combines fast-scanning LC/MS/MS technology with the currently utilized GC/MS screening technique. By merging these two analytical tools, GC/MS and LC/MS/MS, a broader range of drugs can be identified more efficiently and at appropriate drug concentrations for postmortem analysis.

MDME requests funding to purchase instrumentation/supplies to evaluate 1,500 postmortem cases using the combination of GC/MS and LC/MS/MS testing protocols. Overall turnaround time, labor, cost, and the quality of the results will be evaluated and compared to past protocols. The laboratory will incorporate this new screening approach and technology into its routine testing procedures to achieve these objectives:

-Complete development of methodology to screen for 400 drugs, including the newest NPS, as well as routine pharmaceuticals, using full spectra product ion scanning with library matching;

-Replace the current immunoassay screening procedures that are costly and unreliable in modern day screening; and

-Reduce overall costs and turnaround time of the current testing procedures by eliminating additional testing necessary under the old approach.

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