MSACL 2026 Abstract

A Rapid, Low-Solvent Micro-Volume QuEChERS LC-MS/MS Method for Quantifying Emerging Psychoactive Substances in Urine

Su-Chin Chen(1), Shu-Mei Chi(1), Hsiao-Chia Liao(1), Szu-Yin Hsieh(1), Yu-Cheng Li(1), Chia-Long Hsu(1),Hung-Yu Lin(2,3), Mu-Chi Chung(1),Yan-Chiao Mao(1,4), Hsuan-Wei Huang(5)
(1)Department of Medical Toxicology, Taichung Veterans General Hospital, Taichung, Taiwan (2)Department of Food Science, Tunghai University, Taichung, Taiwan (3)Department of Applied Chemistry, Chaoyang University of Technology, Taichung, Taiwan (4)Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan (5)Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan

Su-Chin Chen, Bachelor's Degree (Presenter) Taichung Veterans General Hospital

Presenter Bio: Drug of Abuse Testing (DoA Testing)
New Psychoactive Substances (NPS) Detection
Hair Analysis / Hair Testing
GC-MS (Gas Chromatography-Mass Spectrometry)
LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry)

Relevant Financial Disclosures (within past 24 months, reported on Apr 22, 2026) No relevant financial relationship(s) to disclose. Conflict mitigation NOT REQUIRED.

INTRODUCTION:
Accurate quantification of New Psychoactive Substances (NPS) in urine is critical for forensic and legal determinations. Conventional Solid Phase Extraction (SPE) is labor-intensive, while simple dilution methods often suffer from ESI matrix effects in LC-MS/MS, compromising data integrity. This research establishes an efficient analytical method for NPS and psychotropic substances in urine using Micro-volume QuEChERS pretreatment coupled with LC-MS/MS to minimize matrix interference and improve throughput.

METHODS:
To evaluate the feasibility of the proposed analytical workflow, three sample pretreatment strategies were systematically compared: SPE, direct dilution following centrifugation, and a micro-volume QuEChERS-based extraction method. Upon confirmation of method feasibility, full validation was performed, including assessments of linearity, limit of detection (LOD), lower limit of quantification (LLOQ), selectivity, and matrix effects. For matrix effect evaluation, ten urine specimens from different sources were fortified with target analytes at a threshold concentration of 50 ng/mL. Sample preparation involved combining 200 μL of urine with 200 μL of acetonitrile, followed by micro-volume QuEChERS extraction with vortex mixing for 1 minute. Chromatographic analysis was performed using an Agilent 1290 Infinity II LC coupled to an Agilent 6470 triple quadrupole system, utilizing an InfinityLab Poroshell 120 SB-AQ column (3.0 × 100 mm, 2.7 μm).

RESULTS:
The experimental results demonstrated that the Limit of Quantitation (LOQ) for 7-Aminonitrazepam, 7-Aminonimetazepam, Mephedrone, and Methylephedrine reached 10 ng/mL. Within the concentration range of 10–1000 ng/mL, all targets exhibited excellent linearity (R^2 > 0.995) with high precision (1.2%–5.7%) and accuracy (-9.3%–7.7%). Evaluation of Matrix Effects (ME) and Recovery yielded consistent results across analytes: 7-Aminonitrazepam showed an average ME of 113.8% (CV 8.0%) and recovery of 103.9%; 7-Aminonimetazepam had an average ME of 109.9% (CV 7.9%) and recovery of 97.9%; while Mephedrone and Methylephedrine exhibited average ME of 101.8% and 100.3% respectively, with recoveries near 89%. The Micro-volume QuEChERS pretreatment effectively simplified complex biological matrices, reducing instrument contamination and extending equipment lifespan. Validation with authentic urine samples showed results consistent with GC-MS confirmation, while achieving a processing time 3 to 5 times faster.

CONCLUSION:
Micro-volume QuEChERS is a simple, rapid, and safe procedure with low organic solvent consumption. Its high reproducibility and excellent matrix cleanup capabilities make it an ideal choice for the multi-residue analysis of New Psychoactive Substances (NPS) in forensic and clinical urine testing.