Optimization and Validation of Cannabinoid Metabolite Confirmation in Urine using LC- MS/MS and Biotage EVOLUTE EXPRESS AX SPE Cartridges

Marijuana is one of the most commonly used illicit substances, resulting in it being frequently encountered in clinical samples. The most common sample utilized for drug screening and confirmation in the clinical laboratory is urine. Due to the nature of urine and the various constituents residing in it, sample clean-up can be important. Solid Phase Extraction (SPE) is an effective method for sample clean-up and concentration but can be time consuming to optimize and labor intensive in production. Validation goals for the Biotage EVOLUTE EXPRESS AX cartridges included minimizing the steps in sample preparation for 11-nor-9-Carboxy-delta9THC (THC-COOH) while maximizing robustness and confirming the comparability of the Biotage cartridges to a previously validated SPE product using the same extraction protocol. This is the first report using the Biotage EVOLUTE EXPRESS AX SPE cartridges for THCCOOH analysis with the “EXPRESS” format, eliminating the need to condition and equilibrate prior to sample loading. The EXPRESS format also facilitates uniform flow of samples that may vary in viscosity, providing more rugged results. We also evaluated several previously published strategies to reduce non-specific adsorption of this notoriously difficult analyte.