The interpretation of postmortem γ-hydroxybutyric acid (GHB) concentrations is challenging due to endogenous existence and postmortem GHB production in body tissues and fluids. As an additional complication, formation of GHB was also described in stored postmortem samples. We examined cardiac blood, femoral blood, vitreous humor, cerebrospinal fluid and urine of eight different corpses (male/female 5/3, aged 33–92 years, postmortem interval 1–6 days) where no intake of GHB or one of its precursors was assumed. All samples were collected during autopsy and divided into two aliquots. To one of the aliquots, sodium fluoride (NaF, 1% w/v) was added. Both aliquots were vortexed, further divided into seven aliquots and stored at −20°C. GHB concentrations were measured immediately and subsequently 1 day, 7 days, 2 weeks, 4 weeks, 3 months and 6 months, after sample collection using trimethylsilyl derivatization and gas chromatography, coupled to single quadrupole mass spectrometry. Similar progression curves of GHB concentrations were obtained for the different matrices in the individual corpses. Femoral and cardiac blood GHB concentrations were always found to be higher than in vitreous humor, cerebrospinal fluid, and urine irrespective of stabilization and storage time. None of the obtained GHB concentrations exceed the cutoff values for postmortem matrices commonly used for the identification of an exogenous GHB intake (urine, venous blood and cerebrospinal fluid: 30 mg/L, cardiac blood and vitreous humor 50 mg/L). No significant differences were found for the GHB concentrations measured immediately and 6 months after autopsy. However, we found a significant increase for the GHB concentrations 4 weeks as well as 3 months after sample collection, which was followed by a decrease nearly to initial values. There were no significant differences between samples with and without NaF addition. The data presented are useful for the interpretation of GHB concentrations in upcoming death cases, with special attention to storage conditions and different postmortem matrices.

中文翻译：

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比较研究：心脏血、股血、玻璃体液、脑脊液和尿液中内源性 GHB 的死后长期稳定性，使用和不使用氟化钠稳定剂

由于身体组织和体液中的内源性存在和死后 GHB 的产生，对死后 γ-羟基丁酸 (GHB) 浓度的解释具有挑战性。作为一个额外的并发症，GHB 的形成也被描述在储存的死后样本中。我们检查了八具未摄入 GHB 或其前体之一的不同尸体（男性/女性 5/3，年龄 33-92 岁，死后间隔 1-6 天）的心脏血、股血、玻璃体液、脑脊液和尿液被假定为。在尸检期间收集所有样品并分成两等份。向其中一份等分试样中加入氟化钠（NaF，1% w/v）。两个等分试样都被涡旋，进一步分成七个等分试样并储存在-20°C。立即测量 GHB 浓度，随后测量 1 天、7 天、2 周、4 周、3 个月和 6 个月，在使用三甲基甲硅烷基衍生化和气相色谱收集样品后，与单四极杆质谱联用。对于个体尸体中的不同基质，获得了类似的 GHB 浓度进展曲线。无论稳定和储存时间如何，股骨和心脏血液中的 GHB 浓度总是高于玻璃体液、脑脊液和尿液中的浓度。所获得的 GHB 浓度均未超过通常用于鉴定外源性 GHB 摄入量的验尸矩阵的临界值（尿液、静脉血和脑脊液：30 mg/L，心脏血和玻璃体液 50 mg/L）。尸检后立即和 6 个月测量的 GHB 浓度没有显着差异。然而，我们发现 GHB 浓度在样本采集后 4 周和 3 个月显着增加，随后下降到接近初始值。添加和未添加 NaF 的样品之间没有显着差异。提供的数据有助于解释即将发生的死亡病例中的 GHB 浓度，特别注意储存条件和不同的死后矩阵。