Division of Pharmaceutical Science (Drug Control Centre), Department of Forensic Science and Drug Monitoring, King's College London, London SE1 9NH, UK.
J Anal Toxicol. 2010 Nov;34(9):555-61. doi: 10.1093/jat/34.9.555.
γ-Hydroxybutyrate (GHB) and its metabolic precursor γ-butyrolactone (GBL) are often implicated in cases of drug-facilitated sexual assault (DFSA), although definitive confirmation of GHB/GBL ingestion is complicated by GHB's endogenous nature and rapid elimination following ingestion. Multiple studies have attempted to establish a discriminant limit (generally 10 mg/L) above which urinary GHB concentrations can be considered consistent with GHB/GBL consumption. To supplement the currently available data, a rapid gas chromatography-mass spectrometry method was developed and validated for the analysis of GHB (following acidic conversion to GBL) and used to analyze urine samples collected from 1126 women (mean = 0.84 mg/L, median = 0.68 mg/L, range = 0.00-5.5 mg/L). GHB concentrations were shown to be independent of urinary pH (within the range 4.6-9.3), age (within the range 18-35 years), body mass index (within the range 13.8-36.3), and race. Adjusting GHB concentrations with respect to urinary specific gravity had little effect on the mean value (0.91 mg/L) and range (0.0-7.76 mg/L), although a statistically significant trend of increasing GHB concentration with specific gravity could be observed. Our results can be taken to offer further support for the 10 mg/L discriminant limit for GHB administration in antemortem urine samples.
γ-羟基丁酸（GHB）及其代谢前体 γ-丁内酯（GBL）常与药物辅助性性侵犯（DFSA）有关，尽管由于 GHB 的内源性及其摄入后迅速消除，明确确认 GHB/GBL 的摄入变得复杂。多项研究试图建立一个判别界限（通常为 10mg/L），超过该界限，尿中 GHB 浓度可被认为与 GHB/GBL 的消耗一致。为了补充当前可用的数据，开发并验证了一种快速气相色谱-质谱法，用于分析 GHB（经酸性转化为 GBL 后），并用于分析从 1126 名女性收集的尿液样本（平均值=0.84mg/L，中位数=0.68mg/L，范围=0.00-5.5mg/L）。研究表明，GHB 浓度与尿液 pH（在 4.6-9.3 范围内）、年龄（在 18-35 岁范围内）、体重指数（在 13.8-36.3 范围内）和种族无关。根据尿液比重调整 GHB 浓度对平均值（0.91mg/L）和范围（0.0-7.76mg/L）影响不大，尽管可以观察到随着比重的增加 GHB 浓度呈统计学上显著的趋势。我们的结果可以进一步支持在生前尿液样本中 GHB 给药的 10mg/L 判别界限。
