敌敌畏在血液中的分解动力学研究

Decomposition Kinetics of DDVP in Blood

目的研究敌敌畏在血液中的分解动力学变化规律。方法分解动力学的研究:空白人血分别添加敌敌畏至浓度为0.36、0.72、1.5、3.0、5.3μg/mL,每种浓度再平均分成3组,分别置于20、4、-20℃三种温度条件下保存,于不同时间(1、2、4、6、8、12、16、20、24、28、32、40、48、64、80、96、120d)取样,检测其中敌敌畏的含量;样品的处理:血液中加入乙腈沉淀蛋白,采用Waters BEH C 18(1.7μm 2.1×50mm)柱子,流动相为5m M乙酸铵水溶液-甲醇;流速:0.3mL/min;进样量:2μL,电喷雾离子源(ESI),正离子检测,采用多反应监测方式进行定量分析。结果在不同温度环境下不同浓度的敌敌畏在人血中均存在分解,在-20℃和4℃保存环境下分解符合一级动力学过程一室模型,可以用Ct=Coe-αt表示,在20℃保存环境下分解过快,不宜用动力学方程表示。结论不同浓度的敌敌畏在血液中均存在分解,且在不同保存环境条件下存在很大差异。提示法医工作中对疑似敌敌畏中毒案件,应冷冻保存并及时送检。

Objective To study the decomposition kinetics of dimethyl-dichlorovinylphosphate(abbreviated as DDVP,also dichlorvos)in blood.Methods DDVP was spiked into the blank human blood to make its aliquots with the concentrations of 0.36,0.72,1.5,3.0,5.3μg/mL.Each concentration was respectively stored at the temperature of 20℃,4℃and-20℃for the time of 1,2,4,6,8,12,16,20,24,28,32,40,48,64,80,96 and 120 days,waiting for the test of DDVP content with a UPLC-MS/MS apparatus.The DDVP-spiked blood was deproteinated by acetonitrile,and followed to inject by the volume of 10μL into a Waters BEH C18 column(1.7μm×2.1mm×50mm)that was running with 5mM Ammonium acetatemethanol as the mobile phase under the flow rate of 0.3mL/min.Electro-spray ionization(ESI)source was applied and positive ion mode adopted,plus the multiple reaction monitoring(MRM)mode being used to quantify.Results Differentconditioned temperatures can all cause decomposition of any tested concentrations of DDVP in human blood,with the-20℃and 4℃conditions fitting to the one-compartment open model of first-order kinetics,that is expressed as Ct=Coe-αt.Yet,the decomposition is very fast at 20℃,unable to fit into one kinetic equation.Conclusion DDVP decomposes at the above tested concentrations in blood although there is great discrepancy under different preservation conditions.It is suggested that the case sample of DDVP poisoning should be kept under cold,timely submitted and detected.