Kluge Johanna, Rentzsch Linda, Remane Daniela, Peters Frank T, Wissenbach Dirk K
Institute of Forensic Medicine, Jena University Hospital, Jena, Germany.
Drug Test Anal. 2018 Oct;10(10):1536-1542. doi: 10.1002/dta.2447. Epub 2018 Aug 7.
Urinalysis is well established for drug screening. Various methods of urine adulteration such as dilution, addition of oxidative/reductive chemicals or detergents, and handing over urine-like fluids are used to circumvent a positive screen. Validity parameters such as determination of pH, gravidity, urine temperature, or testing for oxidative/reductive chemicals are therefore used to uncover adulterated urine specimens. However, synthetic urine ("fake urine") has nowadays been used for manipulations, leading to inconspicuous results with common validity test systems. Therefore, the aims of the study were (a) to evaluate additional validity parameters, (b) to evaluate the prevalence of urine adulteration, (c) to identify adulteration markers in purchased fake urine samples. Urine samples (n = 550) submitted for drug abstinence testing were analyzed by a standard urine liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening approach using library-assisted identification of 10 different endogenous biomolecules. The detection rates of biomolecules in authentic samples were phenylalanine (93.4%), tryptophan (97.1%), propionyl-carnitine (67.1%), butyryl-carnitine (99.6%), isovaleryl-carnitine (92.8%), hexanoyl-carnitine (91.0%), heptanoyl-carnitine (97.1%), octanoyl-carnitine (98.9%), and indoleacetylglutamine (98,2%). Phenylacetylglutamine was detected in each authentic sample. Based on the detection rates and measured creatinine levels, six manipulated samples were identified in this study. In two cases, fake urine was handed over, one time fake urine was most likely used for dilution. Once dilution with other fluids was used as adulteration method, while in another sample a detergent solution was handed over. Additionaly, one sample contained reactive chemicals. All fake urine samples were additionally identified by the detection of unique polyglycole patterns, which were observed in purchased fake urine samples.
尿液分析在药物筛查方面已得到广泛应用。为了规避阳性筛查结果，人们采用了各种尿液掺假方法，如稀释、添加氧化/还原化学物质或洗涤剂，以及递交类似尿液的液体。因此，诸如测定pH值、比重、尿液温度或检测氧化/还原化学物质等有效性参数被用于发现掺假的尿液样本。然而，如今合成尿液（“假尿液”）已被用于作弊行为，导致在常见的有效性测试系统中出现难以察觉的结果。因此，本研究的目的是：（a）评估额外的有效性参数；（b）评估尿液掺假的发生率；（c）识别购买的假尿液样本中的掺假标志物。通过标准的尿液液相色谱 - 串联质谱（LC-MS/MS）筛查方法，对提交进行药物戒断测试的550份尿液样本进行分析，采用库辅助鉴定10种不同的内源性生物分子。真实样本中生物分子的检测率分别为：苯丙氨酸（93.4%）、色氨酸（97.1%）、丙酰肉碱（6�1%）、丁酰肉碱（99.6%）、异戊酰肉碱（92.8%）、己酰肉碱（91.0%）、庚酰肉碱（97. ⷁ%）、辛酰肉碱（98.9%）和吲哚乙酰谷氨酰胺（98.2%）。在每份真实样本中均检测到苯乙酰谷氨酰胺。基于检测率和测得的肌酐水平，本研究中识别出6份掺假样本。其中2例是递交了假尿液，1例很可能是使用假尿液进行了稀释。有1次使用与其他液体混合进行稀释作为掺假方法，而在另一个样本中递交的是洗涤剂溶液。此外，有1个样本含有反应性化学物质。所有假尿液样本还通过检测独特的聚乙二醇模式得以识别，这些模式在购买的假尿液样本中被观察到。
