New Derivatization Method for Quantitative Analysis of Δ⁹-THC-COOH in Urine

User Benefits

- The risk of limited availability of stable isotope-labeled standards can be avoided by synthesizing internal standards through derivatization. - The derivatizing agent IPPAH and its corresponding stable isotope IPPAH-d₆ can be synthesized easily and inexpensively from acetone (or acetone-d₆). - This approach achieves sufficient sensitivity and quantitative accuracy for the determination of Δ⁹-THC-COOH in urine.

Introduction

In Japan, the Cannabis Control Act and the Narcotics and Psychotropics Control Act were amended in December 2024. While cannabis was legalized for industrial and medical uses, stricter cannabis regulations have been enacted to prevent harm from its abuse. The primary psychoactive cannabinoid, delta-9-tetrahydrocannabinol (Δ⁹-THC), is extensively metabolized in the body and is excreted mainly in urine and feces as 11-nor-9-carboxy-THC (Δ⁹-THC-COOH) and its glucuronide conjugates. Consequently, Δ⁹-THC-COOH must be analyzed to confirm cannabis use. For LC-MS/MS quantitation, the stable isotope-labeled internal standard Δ⁹-THC-COOH-d₃ is commonly used to correct for matrix effects. However, most suppliers of stable isotope standards are located in the U.S., making these standards difficult to obtain due to import procedures. Furthermore, there may be additional import-related supply risks for stable isotope standards in the future. This Application News describes a technique for quantitating Δ⁹-THC-COOH using an internal standard that is synthesized easily and inexpensively by derivatization with IPPAH (1-isopropylpiperidine carboxylic acid hydrazide), which characteristically reacts with carboxyl groups, and its corresponding stable isotope IPPAH-d₆.

August 24, 2026 GMT