气相动态顶空进样法是一种简单、环保和高灵敏度的样品前处理方法,在水样中挥发性有机物监测中的运用还有待研究.本研究应用气相动态顶空进样-气相色谱-质谱联用法测定饮用水源水中57种挥发性有机污染物,通过对比实验,优化了影响气相动态顶空进样方法灵敏度的主要因素,确定了较佳的样品盐度(30％)、平衡温度(40℃)、平衡时间(20 min)、吹脱捕集气流速(60 mL/min)及吹脱捕集时间(2 min)等前处理方法参数.采用优化的水样前处理条件,挥发性有机物标准曲线线性相关系数均大于0.9930(环氧氯丙烷为0.9821除外),方法检出限为0.2～7.0μg/L,实际饮用水源水样品加标回收率为82.1％ ～ 143％,精密度(RSD)为0.1％～24％(n=3).建立的气相动态顶空进样法,水样前处理过程自动化,可同时对水中几十种挥发性有机物进行分析,提高了分析效率；与常见的对水样气相和液相中目标物同时进行吹脱捕集的吹扫捕集法相比,因无需直接接触水样而减少了样品对仪器的污染.%A large number of measurement work on organochlorine and organophosphorus pesticide residue in soil was carried out in China' s environmental pollution survey evaluation and test project. The simultaneous measurements of a variety of organic pollutants were a new research hotspot. In this study, the pesticide residues of 9 kinds of organochlorine such as hexachlorobenzene and 13 kinds of organophosphorus such as dichlorvos were simultaneously measured by Gas Chromatography with n-hexane-acetone (volume ratio 1 : 1) for extracting agent, the accelerated solvent extraction and capillary column. The recoveries were from 79. 1% to 107. 7% , relative standard deviations were from 3. 62% to 9. 94% (n =7) and detection limits were from 0. 02 to 0. 45 jxg/kg. This method simultaneously extracted the two kinds of pesticides and completely separated the various components, which extended the application field. Comparing with the traditional ultrasonic extraction and Soxhlet extraction method, extracting time of this method was reduced to 20 min and extraction solvent volume was down to 50 mL, which saved the analytical time and reduced the cost. Meanwhile, the precisions and recoveries met the requirements of the national environmental pollution survey and assessment.
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