Liu Yuming, Zhang Xinyu, Li Jiaolun, Huang Zhibin, Lin Zebin, Wang Jingru, Zhang Chengqiang, Rao Yulan
Zhongshan Hospital, Fudan University, 180 Fenglin Road, Xuhui District, Shanghai 200032, PR China.
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, PR China.
J Anal Toxicol. 2018 Jun 1;42(5):346-352. doi: 10.1093/jat/bky010.
The lack of systematic studies on the stability of ethanol's non-oxidative metabolites in postmortem specimens restricts their use in forensic cases. This study aimed to compare the stability of ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanols (PEths) and fatty acid ethyl esters (FAEEs) in postmortem human blood. Three groups were established based on the level and source of ethanol: the blank group, the ethanol-spiked group and the ethanol-positive group. Each group contained six blood samples from different corpses. The samples in each group were placed at 37, 25, 4 and -20°C. Every 24 h for 7 days, 50 μL was collected from each sample. The levels of EtG, EtS, PEths and FAEEs were determined by liquid chromatography-mass spectrometry, and their stability was evaluated. EtG was not detected in the blank group, but it was found in samples in the ethanol-spiked group placed at 37°C, and it was degraded in the ethanol-positive group at 37 and 25°C. EtS showed no change in any of the groups. PEths were not detected in the blank group, but formation was found in the ethanol-spiked group at all temperatures. In the ethanol-positive group, PEth levels fluctuated at 37°C, decreased at 25°C and increased at -20°C. FAEEs were generated in the blank group and in the ethanol-spiked group at all temperatures. In the ethanol-positive group, FAEEs were degraded at 37 and 25°C but were generated at 4 and -20°C. EtS is a reliable biomarker of ethanol consumption, and EtG could be used as a biomarker at low temperatures (4 and -20°C), but PEths and FAEEs are not appropriate biomarkers of ethanol consumption.
缺乏对死后标本中乙醇非氧化代谢物稳定性的系统研究限制了它们在法医案件中的应用。本研究旨在比较死后人体血液中葡萄糖醛酸乙酯（EtG）、硫酸乙酯（EtS）、磷脂乙醇（PEths）和脂肪酸乙酯（FAEEs）的稳定性。根据乙醇的水平和来源建立了三组：空白组、乙醇添加组和乙醇阳性组。每组包含来自不同尸体的六个血液样本。每组样本分别置于37、25、4和 -20°C。在7天内每隔24小时从每个样本中采集50 μL。通过液相色谱 - 质谱法测定EtG、EtS、PEths和FAEEs的水平，并评估它们的稳定性。空白组未检测到EtG，但在置于37°C的乙醇添加组样本中发现了EtG，且在37和25°C的乙醇阳性组中EtG发生了降解。EtS在任何组中均未显示变化。空白组未检测到PEths，但在所有温度下的乙醇添加组中均发现有PEths生成。在乙醇阳性组中，PEth水平在37°C时波动，在25°C时下降，在 -20°C时升高。空白组和乙醇添加组在所有温度下均生成FAEEs。在乙醇阳性组中，FAEEs在37和25°C时降解，但在4和 -20°C时生成。EtS是乙醇摄入的可靠生物标志物，EtG可在低温（4和 -20°C）下用作生物标志物，但PEths和FAEEs不是乙醇摄入的合适生物标志物。
