Department of Pathology and Laboratory Medicine, University of Miami Miller School of Medicine, Rosenstiel Medical Science Building (RMSB), 1600 NM 10th Avenue, 7th Floor Suite 7020 (R-5), Miami, USA.
J Anal Toxicol. 2019 Oct 17;43(9):734-745. doi: 10.1093/jat/bkz066.
Toxicology laboratories commonly employ immunoassay methodologies to perform an initial drug screen on urine specimens to direct confirmatory testing. Due to limitations of immunoassay testing and the need to screen for a broader range of drugs with lower limits of detection at a lower cost, mass spectrometry screening techniques have gained favor in the toxicology field. A liquid chromatography-tandem mass spectrometry (LC-MS-MS) urine screening panel was developed and validated for 52 drugs and metabolites. A simple dilute-and-shoot with enzymatic hydrolysis technique was utilized to prepare the urine specimens for analysis. Limit of detection, interference, ionization suppression/enhancement, carryover and stability of processed specimens were assessed during validation. To evaluate the toxicological results obtained from utilizing the LC-MS-MS in comparison with the laboratory's current enzyme-linked immunosorbent assay (ELISA) panel, 100 authentic urine specimens from suspected driving under the influence and drug-facilitated crime cases were analyzed using both methodologies and the results were compared. In addition, the cost of each methodology was evaluated and compared. The validated LC-MS-MS method had limits of detection that were equal to or lower than the concentrations validated for ELISA cutoffs, had fewer exogenous interferences, and the cost of screening per specimen was reduced by ~70% when compared to ELISA. Comparing the toxicology results of forensic urine specimens demonstrated that by only using ELISA, the laboratory was unable to detect benzoylecgonine in 26%, lorazepam in 33% and oxymorphone in 60% of the positive specimens. Additional analytes detected using the LC-MS-MS method were zolpidem and/or metabolite, gabapentin, tramadol and metabolite, methadone and metabolite, meprobamate and phentermine. The results of the validation, the toxicological result comparison and the cost comparison showed that the LC-MS-MS screening method is a simple, sensitive and cost-effective alternative to ELISA screening methods for urine specimens.
毒理学实验室通常采用免疫分析法对尿液样本进行初步药物筛选，以指导确证性检测。由于免疫分析检测存在局限性，且需要以更低的成本筛选出更多种类、更低检测限的药物，因此质谱筛选技术在毒理学领域得到了广泛应用。本研究开发并验证了一种用于 52 种药物及其代谢物的液相色谱-串联质谱（LC-MS-MS）尿液筛选检测方法。采用简单的稀释-进样和酶解技术对尿液样本进行前处理，以用于分析。在验证过程中评估了检测限、干扰、离子抑制/增强、交叉污染和处理后样本的稳定性。为了评估与实验室当前酶联免疫吸附测定（ELISA）检测方法相比，利用 LC-MS-MS 获得的毒理学结果，本研究采用两种方法分析了 100 份来自疑似酒后驾车和药物犯罪案件的真实尿液样本，并对结果进行了比较。此外，还评估并比较了两种方法的成本。验证后的 LC-MS-MS 方法的检测限与 ELISA 检测方法的截止值相当或更低，外源性干扰更少，与 ELISA 相比，每个样本的筛查成本降低了约 70%。通过比较法医尿液样本的毒理学结果，本研究发现，如果仅使用 ELISA 方法，实验室无法检测到 26%的苯甲酰可龙、33%的劳拉西泮和 60%的羟吗啡酮。使用 LC-MS-MS 方法还检测到唑吡坦及其代谢物、加巴喷丁、曲马多及其代谢物、美沙酮及其代谢物、甲丙氨酯和苯丁胺。验证结果、毒理学结果比较和成本比较表明，与 ELISA 筛选方法相比，LC-MS-MS 筛选方法是一种简单、灵敏、经济有效的尿液样本筛选方法。
