Green liquid-liquid microextraction for quantification of ketamine and metabolites in human urine by gas chromatography-mass spectrometry.
Hsueh-Hui Yang, Chia-Sui Kao, Ahai C Lua, Tsong-Yung Chou
Journal of analytical toxicology May 16, 2025 DOI: 10.1093/jat/bkaf022 via PubMed
Summary
AI-generated from the abstractA green method using liquid-liquid microextraction with 1-undecanol and gas chromatography-mass spectrometry detected ketamine and its metabolites in human urine without derivatization. Detection limits were 1.0 ng/mL for ketamine, 1.5 ng/mL for norketamine, and 1.7 ng/mL for dehydronorketamine. Analysis of eight real urine samples from drug abusers showed acceptable accuracy and precision. The findings suggest that detecting dehydronorketamine may be more suitable than detecting norketamine or ketamine for judging ketamine abuse. The method is simple, fast, and uses little solvent, addressing the need for green analytical techniques in toxicology.
Study at a glance
| Characteristics | Method development and validation Peer reviewed |
|---|---|
| Sample size | 8 |
| Population | Drug abusers providing urine samples |
| Keywords | Green-chemistry Analytical-methods Forensic-toxicology Drug-testing Ketamine-detection |
| Citations | 2 |
| Key finding | Detection of dehydronorketamine in urine may be more suitable than norketamine or ketamine for judging ketamine abuse. |
Abstract
This study aimed to develop and validate a green method for the detection of ketamine and its metabolites in human urine samples and subsequently determine which metabolite is more suitable for judgment of ketamine abuse. Ketamine and its metabolites were extracted from urine samples with 1-undecanol using liquid-liquid microextraction based on the solidification of floating organic droplet extraction. The extracts were directly analyzed using gas chromatography-mass spectrometry (GC-MS) without derivatization. The sample pretreatment procedure prior to GC-MS analysis was simple, fast, and required little solvent consumption. Parameters that affect the extraction efficiency, including pH of the urine sample and centrifugation speed, were optimized. Under the optimized conditions, the limits of detection for norketamine, dehydronorketamine, and ketamine were 1.5, 1.7, and 1.0 ng/mL, respectively. The method was used to analyze eight real urine samples from drug abusers and exhibited acceptable accuracy and precision. By analyzing real samples, this study revealed that detection of dehydronorketamine in urine samples for the judgment of ketamine abuse may be more suitable than detection of norketamine or ketamine. The method used in this study addresses the need for green analytical techniques in toxicology.