气相色谱法测定血浆中毒死蜱及其主要代谢产物

Determination of chlorpyrifos and its metabolite in plasma by GC

目的建立一种灵敏、准确测定血浆中毒死蜱（chlorpyrifos,CPF）及其主要代谢物3,5,6-三氯-2-吡啶醇（3,5,6-trichloro-2-pyridinol,TCP）的气相色谱（GC）方法。方法取0.5 m L家兔血浆加入乙酸乙酯进行液液萃取,离心后取上层有机相,氮气40℃吹干,残留物加入乙酸乙酯定容后,再加入N-甲基叔丁基二甲基硅基三氟乙酰胺（MTBSTFA）,50℃下对TCP进行衍生1 h。样品采用气相色谱仪进行检测,以HP-5毛细管柱分离,电子捕获检测器检测。以待测物质的保留时间定性,外标法峰面积定量。结果 CPF和TCP在8 min内得到良好分离。CPF和TCP的质量浓度在0.01-2.50 mg/L的线性范围内与峰面积相关性良好,相关系数分别为0.999 7和0.999 8;最低检测限均为1μg/L;精密度RSD均小于10%;加标回收率分别为77.60%-106.16%和72.00%-99.86%。结论此方法灵敏准确,简便可靠,可用于血浆中CPF与TCP的含量分析。

Objective To develop a simple and sensitive method for simultaneous determination of chlorpyrifos [O,O-diethyl-O-（3,5,6-trichloro-2-pyridinyl）phosphorothioate,CPF] and its specific metabolite 3,5,6-trichloro-2-pyridinol（TCP）in plasma by GC.Methods Plasma of rabbit（0.50 m L） was extracted by ethylacetate.After purification and centrifugation,the organic layer was evaporated with a stream of nitrogen at 40 ℃.The residue was dissolved in ethylacetate,and TCP was derivatized for an hour at 50 ℃ with N-（tert-butyldimethylsilyl）-N-methyltrifluoroacetamide（MTBSTFA）.Then the sample was injected into the GC system with HP-5 column and ECD.Qualitative analysis was made by the retention time and quantitative analysis by external standard curve.Results Precise separation of CPF and TCP was achieved within 8 minutes.The relationship between peak areas and concentration showed a good linearity in a range from 0.01 to 2.50 mg/L for both CPF and TCP（r = 0.999 7,0.999 8,respectively）.The limits of detection were 1μg/L for both CPF and TCP.Percentage recoveries of this procedure in different matrix were between 77.60%-106.16% for CPF,and between 72.00%-99.86% for TCP.The RSDs of the variation were both lower than 10%.Conclusion This proposed method is simple,reliable and sensitive for simultaneous determination of CPF and its metabolite TCP in plasma samples with satisfactory results.