水中微囊藻毒素的氧化水解产物2-甲基-3-甲氧基-4-苯基丁酸的气相色谱-质谱检测研究

Determination of 2-Methyl-3-Methoxy-4-Phenylbutanoic Acid Derived from Oxidation and Hydrolyzation of Microcystin in Water by Gas Chromatograph Mass Spectrometry

[目的]采用衍生化建立一个便捷和高效的水中微囊藻毒素（MC）氧化产物2-甲基-3-甲氧基4苯基丁酸（MMPB）气相色谱-质谱仪联用（GC-MS）的检测方法。[方法]高锰酸钾氧化水样，正己烷萃取，浓缩，六氟异丙醇-二乙胺N，N-二异丙基碳酰二亚胺（HFIP．DIC）衍生化，GC-MS检测，内标法定量。[结果]通过对水样氧化水解和MMPB衍生化条件的优化，以GC-MS检测MMPB的方法检测限（MDL）为0．101gg／L（浓度均以总MC计），线性范围为0．2～10．0μg／L，具有良好的准确度（80％-120％）、精密度（RSD〈15％）和重复性（RSD〈15％），样品监测浓度水平为〈0．101～3．090μg／L。[结论]本方法对水中MC总量的分析提供了快速、简便、可靠的方法，能用于对日常水质中MC总量的监测分析研究。

[ Objective ] To develop a method for simple and rapid determination of 2-methyl-3-methoxy-4-phenylbutyric acid （MMPB）, an oxidation and hydrolyzation product of microcystin （MC） in water using gas chromatography-mass spectrometry （GC-MS）. [ Methods ] Samples were oxidized with potassium permanganate, extracted using n-hexane, then derivatized with hexafluoroisopropanol （HFIP）/N, N＇-diisopropylcarbodiimide （DIC）, and finally detected by GC-MS and quantified using internal standard method. [ Results ] The method was validated in terms of method detection limit （MDL） （0.101 μg/L）, linearity range （0.2-10.0 μg/L）, accuracy （80%-120%）, precision （relative standard deviation, RSD〈15%）, and repeatability （RSD〈15%）. The representative samples were successfully detected with concentrations between 〈 MDL and 3.090μg/L. [ Conclusion ] The proposed method as an alternative method of HPLC-MS/MS is practicable for the routine analysis of total microcystins in water.