Cook J D, Caplan Y H, LoDico C P, Bush D M
University of Maryland, School of Medicine, Department of Medical and Research Technology, Baltimore 21201, USA.
J Anal Toxicol. 2000 Oct;24(7):579-88. doi: 10.1093/jat/24.7.579.
One challenge facing the laboratory forensic toxicologist today is verifying the validity of the random urine specimen submitted for workplace drugs of abuse analysis. Determining whether urine substitution has occurred is best accomplished through the inspection of the specimen's appearance and the performance of specific laboratory tests, such as determining the concentration of biochemical metabolic waste products and measuring indices of urine concentration. Criteria for classifying submitted urine as substituted are postulated after an extensive review of the published scientific literature. Relevant studies that were evaluated include normal random urine reference interval studies, clinical studies involving the analysis of random urine specimens, theoretical dilutional limits, medical conditions resulting in overhydration, and water-loading studies. After compilation of the study data, derived substituted criteria of urinary creatinine < or = 5.0 mg/dL and urinary specific gravity < or = 1.001 are suggested. A urine specimen meeting these criteria may be considered substituted because it is not consistent with the clinical characteristics associated with normal human urine.
当今，实验室法医毒物学家面临的一项挑战是验证提交用于工作场所药物滥用分析的随机尿液样本的有效性。确定是否发生尿液替换的最佳方法是检查样本外观并进行特定的实验室检测，例如测定生化代谢废物产物的浓度以及测量尿液浓度指标。在广泛查阅已发表的科学文献之后，提出了将提交的尿液归类为被替换尿液的标准。所评估的相关研究包括正常随机尿液参考区间研究、涉及随机尿液样本分析的临床研究、理论稀释极限、导致水合过度的医学状况以及水负荷研究。在汇总研究数据之后，建议将尿肌酐≤5.0mg/dL和尿比重≤1.001作为推导得出的被替换标准。符合这些标准的尿液样本可能被视为被替换样本，因为它与正常人类尿液相关的临床特征不一致。
