背景:硫化氢(H2S),内源性气体,也可以从有机物腐败产生。疑似H2S中毒的病例很难确定标本中的H2S是由死前中毒摄入的还是由有机物腐败产生的。本研究的目的是通过比较样品中H2S及其代谢物随时间的浓度来寻找急性H2S中毒的生物标志物。
方法:建立H2S加血和空白血型。由于有机物腐败,研究了H2S的分解动力学和事后产生。将样品放置在37、20、4和-20℃的4个条件下。采用气相色谱-质谱法对标本中H2S的含量进行定量,并通过液相色谱-质谱法测定其代谢产物(硫代硫酸盐和三甲基锍)的含量,并对其浓度的变化进行了评价。
结果:在含H2S的血液中,H2S在37、20和4°C的初始阶段急剧下降,先升后降;但在-20℃时相对稳定。在尖刺的血液中,硫代硫酸盐比内源浓度高9倍,在储存过程中先增加后减少。除37°C的硫代硫酸盐外,空白血中的H2S和硫代硫酸盐均在储存中先升高后降低;但两组中的三甲基锍(TMS)随时间逐渐降低。
结论:硫代硫酸盐是-20℃急性H2S中毒7天内的可靠生物标志物。但是H2S,由于不稳定性和波动性,不是理想的中毒标记.由于血液中的浓度极低,TMS不是合适的生物标志物。
BACKGROUND: Hydrogen sulfide (H2S), an endogenous gas, can also be generated from organics putrefaction. It is difficult for suspected cases of H2S poisoning to determine whether H2S in specimens is ingested by antemortem poisoning or generated from organics putrefaction. The aim of this study was to find the biomarkers of acute H2S poisoning via comparing the concentrations of H2S and its metabolites over time in specimens.
METHODS: The H2S-spiked blood and blank blood group were established. The decomposition kinetics and the postmortem production of H2S were studied due to organics putrefaction. The specimens were placed under 4 conditions of 37, 20, 4 and - 20 ℃. The content of H2S in specimens was quantified by gas chromatography-mass spectrometry, and the contents of its metabolites (thiosulfate and
trimethylsulfonium) were measured by liquid chromatography-mass spectrometry, and the variation of its concentration was evaluated.
RESULTS: In H2S-spiked blood, H2S decreased sharply in the initial stage at 37, 20 and 4 °C, and increased first and then decreased later; but it was relatively stable at - 20 °C. In spiked blood, thiosulfate was 9-fold higher than endogenous concentrations, which increased at first and then decreased during storage. Except for thiosulfate at 37 °C, H2S and thiosulfate in blank blood both increased at first and then decreased in storage; but
trimethylsulfonium (TMS) gradually decreased over time in both groups.
CONCLUSIONS: Thiosulfate is a reliable biomarker of acute H2S poisoning at - 20℃ within 7 days. But H2S, because of instability and volatility, is not an ideal poisoning marker. TMS is not an appropriate biomarker due to extremely low concentration in blood.