Quantitative Analysis of THC and its Metabolites in Plasma Using Oasis PRiME HLB for Toxicology and Forensic Laboratories

Introduction

Amongst forensic toxicology laboratories, cannabis is one of the most frequently encountered drugs.¹ For most forensic laboratories providing toxicological analyses, the confirmation, and quantification of Δ9-tetrahydrocannabinol (THC) and its primary metabolites in whole blood or plasma is high on the list of requests from clients and enforcement agencies, such as district attorneys and/or police departments (city, county, or state levels).² While whole blood is often used in postmortem forensic cases, whole blood/plasma ratios can be quite inconsistent, particularly for COOH-THC.³ Therefore, for pharmacokinetic studies involving medicinal uses or behavioral effects, plasma is often a preferred matrix.^4,5 The ability to efficiently extract and quickly analyze samples submitted by such agencies is seen as a definite benefit to the laboratory. In this application, the efficient extraction and accurate quantification of THC and two major metabolites, THC-COOH and THC-OH, is achieved using a novel solid-phase extraction (SPE) sorbent, Oasis PRiME HLB, coupled with fast analysis using LC-MS/MS. This method offers a great solution for laboratories looking to incorporate this type of analysis into their methodology portfolio.