Impact of isomeric differences between internal standard and analyte for the LC-MS/MS quantification of 11-Nor-delta9-THC-9-carboxylic acid glucuronide

Authors: Sarah Aijaz, Alexander Wong, Isil Dilek, and Uma Sreenivasan
Presented at The American Society for Mass Spectrometry (ASMS), St. Louis, MO, May 31-June 4, 2015
Abstract
(-)-trans-11-Nor-delta9-tetrahydrocannabinol-9-carboxylic acid (THC acid) and THC acid glucuronide are urinary metabolites of (-)-trans-tetrahydrocannabinol (THC), an active constituent of marijuana. Chemical synthesis of THC acid and its glucuronide is complex and low yielding; the materials are not widely available. Development of reference standards focused on the most feasible diastereomers. The (+)-trans-isomer was synthesized and developed as a certified reference material for quantification of THC acid glucuronide by LC-MS/MS. (±)-cis- THC acid-D3-glucuronide was developed as an internal standard. This study investigates the feasibility of (±)-cis-THC acid-D3-glucuronide as an internal standard for the LC-MS/MS quantitative analysis of THC acid glucuronide