台灣正常組群尿液及唾液內生性珈瑪-羥基丁酸（GHB）參考值之調查研究

γ-羥基丁酸（Gamma-hydroxybutyric acid, GHB）是一種人體內生性物質，也是三大性侵藥品之一。目前GHB 的檢測在臨床和法醫學上已然非常重要，本研究利用真實尿液和唾液檢體，並以N-Methyl-N(trimethylsily) trifluoroacetamide（MSTFA）作為衍生化試劑，最後用氣相層析質譜儀（GC-MS）來進行最後分析，以此結果希望能夠成為一個台灣正常人群體內GHB 濃度之參考範圍。本研究分別收集了60 件真實尿液檢體和60 件真實唾液檢體，通過前處理方法得到了最低偵測極限（LOD）0.05 μg/mL 和定量極限（LOQ）0.2 μg/mL，且檢量線最高濃度可達到10000 ng/mL。最後，實驗結果顯示，尿液中GHB 之平均濃度為1.65 μg/mL（0.07～6.21 μg/mL），而唾液中平均濃度為0.2μg/mL（0.05～1.75 μg/mL）。根據本研究之統計數據，GHB 的法定閾值尿液建議訂為10 μg/mL，而唾液之閾值則可為4 μg/mL。

Gamma-hydroxybutyrate （ GHB ） , an endogenous production substance inmammalian brain, is one of three common date rape pills. Laboratory detection of GHBin urine is important for clinical and forensic applications. We have developedN-Methyl-N (trimethylsily) trifluoroacetamide （MSTFA）chemical derivatizationfollow by gas chromatography-mass spectrometry （GC-MS） method for the detectionof low levels of GHB in urine and salivary and have used this method to establish areference range for normal population in Taiwan. The in house method was validatedfor the analysis of GHB and was used to analyze urine samples and salivary fluidcollected from 60 and 60 healthy subjects, respectively. The limits of detection （LOD）and quantitation（LOQ）obtained via this approach were 0.05 and 0.2 μg/mL,respectively. The calibration curve exhibited linearity for all analyses with an upperlimit of linearity of 10000 ng/mL. The mean concentration of GHB was 1.65 μg/mL（0.07～6.21 μg/mL）in urine and 0.2 μg/mL（0.05～1.75 μg/mL）in salivary fluid.These data that led us to suggest cut off value for GHB is 10 μg/mL in urine and 4μg/mL in salivary fluid.