Rapid and sensitive dilute-and-shoot analysis using LC-MS-MS for identification of multi-class psychoactive substances in human urine

Huei-Wen Chen; Hsin-Tung Liu; Yun-Ning Kuo; Da-Peng Yang; Te-Tien Ting; Jung-Hsuan Chen; Jui-Yi Chiu; Yung-Cheng Jair; Hsu-Cheng Li; Pin-Ju Chiang; Wei-Ru Chen; Mei-Chih Lin; Ya-Hui Hsu; Pai-Shan Chen

doi:10.1016/j.jpba.2023.115443

Rapid and sensitive dilute-and-shoot analysis using LC-MS-MS for identification of multi-class psychoactive substances in human urine

J Pharm Biomed Anal. 2023 Sep 5:233:115443. doi: 10.1016/j.jpba.2023.115443. Epub 2023 May 5.

Authors

Affiliations

¹ Graduate Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC.
² School of Big Data Management, Soochow University, Taipei, Taiwan, ROC.
³ Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan, ROC.
⁴ Taiwan Food and Drug Administration, Taipei, Taiwan, ROC.
⁵ Graduate Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC. Electronic address: paishanchen@ntu.edu.tw.

PMID: 37210892
DOI: 10.1016/j.jpba.2023.115443

Abstract

The emergence of new psychoactive substances currently exceeding a thousand is rapidly changing substance prevalence patterns and straining the methods used for detection, most of which are suitable only for a single class of substances. This study presents a rapid and facile dilute-and-shoot system operated in conjunction with an optimized liquid chromatographic separation system for the high-sensitivity detection of substances across a range of substance classes with 3 isotopes used only. The proposed method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) is able to identify 68 substance and their metabolites in urine samples as small as 50 μL. Optimal chromatographic conditions including 95% water/methanol ratio with 0.1% added formic acid and a prolonged LC gradient run-time (15 min) improved the peak shape of polar compounds and enhanced signal strength by 5%. Under 4-fold dilution, all analytes were within 80-120% of tolerance response levels, indicating that the matrix effect was insignificant. In experiments, the limit of detection (LOD) ranged from 0.05 to 0.5 ng mL^-1, while the coefficient of determination (R²) was > 0.9950. The retention time shift of each peak remained at < 2% with an inter-day relative standard deviation (RSD) of 0.9-14.9% and intra-day RSD of 1.1%- 13.8%. The rapid dilute-and-shoot presents a high-sensitivity, significant stability, robustness and reproducibility without serious interference. To demonstrate the effectiveness of the system, 532 urine samples were collected from suspected drug abusers, and the proposed method was used for rapid analysis. Of these samples, 79.5% contained between one and twelve analytes, and 12.4% tested positive for new psychoactive substances, mostly derivatives of amphetamine and synthetic cathinones. The study presents a high-sensitivity analytic system that is capable of detecting substances from multiple classes and can be used for effective monitoring of substance prevalence in urine.

Keywords: Dilute-and-shoot; Liquid chromatography-mass spectrometry; Multi-class psychoactive substances; Solid phase extraction; Urine.

MeSH terms

Amphetamine
Central Nervous System Agents*
Chromatography, High Pressure Liquid / methods
Chromatography, Liquid / methods
Humans
Limit of Detection
Reproducibility of Results
Tandem Mass Spectrometry* / methods

Substances

Central Nervous System Agents
Amphetamine