From the Department of Pathology, University of Mississippi Medical Center, Jackson.
Arch Pathol Lab Med. 2020 Feb;144(2):168-171. doi: 10.5858/arpa.2019-0197-OA. Epub 2019 Nov 22.
CONTEXT.—: Synthetic urine products are commercially marketed for the purpose of specimen substitution for urine drug screens. These products are widely popular because they yield negative drug screen results, meet criteria for specimen validity testing, and are easily accessible and affordable. Current specimen validity criteria are ineffective for detecting these synthetic products, and new markers of specimen validity are required.
OBJECTIVE.—: To develop and evaluate a multicomponent liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for urine specimen validity testing.
DESIGN.—: A quantitative LC-MS/MS assay was developed for caffeine, cotinine, theobromine, and urobilin in urine. The assay was applied to known synthetic urine products (n = 10) as well as human specimens received for pre-employment testing (n = 500), for-cause workplace testing (n = 100), and medical pain management monitoring (n = 200). Specimens devoid of all 4 validity markers were subjected to follow-up testing that involved microscopic urinalysis and comprehensive gas chromatography mass spectrometry for drugs, pharmaceuticals, hormones, and lipids.
RESULTS.—: Of the experimental groups, 10 of 10 synthetic urine products (100%), 12 of 500 pre-employment specimens (2.4%), and 4 of 200 pain management specimens (2.0%) failed the experimental LC-MS/MS assay. Follow-up testing indicated that each of the failed specimens was nonphysiologic in nature.
CONCLUSIONS.—: Simultaneous application of the 4 experimental validity markers appeared to be a robust method for detecting nonphysiologic specimens. New markers of specimen validity must be developed in order to identify commercially available synthetic urine products.
合成尿液产品被商业化用于替代尿液药物检测样本。这些产品因其能产生阴性药物检测结果、符合标本有效性检测标准，以及易于获得和负担得起而广受欢迎。目前的标本有效性标准无法检测到这些合成产品，需要新的标本有效性标志物。
开发和评估尿液标本有效性检测的多组分液相色谱串联质谱（LC-MS/MS）分析方法。
开发了一种用于尿液中咖啡因、可替宁、可可碱和尿胆素的定量 LC-MS/MS 分析方法。该分析方法应用于已知的合成尿液产品（n = 10）以及用于入职前检测（n = 500）、因由工作场所检测（n = 100）和医疗疼痛管理监测（n = 200）的人体标本。没有所有 4 个有效性标志物的标本进行了后续测试，包括显微镜尿液分析和用于药物、药物、激素和脂质的全面气相色谱-质谱法。
在实验组中，10 个合成尿液产品（100%）、500 个入职前标本（2.4%）和 200 个疼痛管理标本（2.0%）中的 12 个和 4 个未能通过实验性 LC-MS/MS 分析。后续测试表明，每个失败的标本都是非生理性的。
同时应用 4 种实验有效性标志物似乎是检测非生理性标本的有效方法。必须开发新的标本有效性标志物，以识别市售的合成尿液产品。
