Evaluation of biochemical assays and optimization of LC–MS-MS analysis for the detection of synthetic urine

Author:

Franke Laura1ORCID,Fuczik Christian2,Hubig Michael1,Peters Frank T1ORCID,Wissenbach Dirk K1ORCID

Affiliation:

1. Jena University Hospital, Institute for Forensic Medicine, Friedrich Schiller University Jena , Germany

2. Drogentest Wien , Heinestraße 1, Vienna 1020, Austria

Abstract

Abstract Ensuring specimen validity is an essential aspect of toxicological laboratories. In recent years, substituting authentic urine specimens for synthetic urine (SU) has become increasingly popular. Such SU products consist of components expected in normal urine and show physiological values for specific gravity and pH. Thus, standard specimen validity testing may fail in revealing adulteration by SU. The present study investigated three methods to distinguish authentic and SU specimens: enzymatic detection of uric acid, the commercially available Axiom Test True SU and liquid chromatography coupled with (tandem) mass spectrometry (LC–MS-MS) analysis of 10 endogenous biomolecules. Additionally, novel direct markers of SU were investigated. Two specimen sets were analyzed by each method. Specimen set A consisted of eight SU products purchased from the Austrian/German market and 43 urine specimens from volunteers of known authenticity, which underwent double-blind analysis. Specimen set B consisted of 137 real urine specimens submitted for drug testing, which were selected due to initial suspicious test results in adulteration testing and reanalyzed by all three methods. Uric acid and LC–MS-MS-based endogenous biomolecule testing showed 100% sensitivity and specificity for set A. The commercial test had 87.5% sensitivity and 97.7% specificity for set A. For set B, uric acid and LC–MS-MS analysis showed almost similar results, even if uric acid was missing one presumptive authentic urine specimen according to LC–MS-MS findings. Nearly half of the SU assignments for the commercial test were presumptive false positives. New SU markers were observed for SU products from the Austrian/German market. One specimen in set B had both an endogenous biomolecule pattern and SU markers suggesting urine dilution with SU. In conclusion, several analytes or methods should be used rather than one, and the most reliable results are achieved if both indirect and direct markers of urine substitution are analyzed.

Publisher

Oxford University Press (OUP)

Subject

Chemical Health and Safety,Health, Toxicology and Mutagenesis,Toxicology,Environmental Chemistry,Analytical Chemistry

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3