盐析-顶空气相色谱法测定麦芽酚生产废水中的二氯甲烷和1,2-二氯乙烷

Determination of Dichloromethane and 1,2-Dichloroethane in Maltol Production Wastewater by Salting out Combined with Headspace Gas Chromatography

本文采用盐析-顶空气相色谱法测定麦芽酚生产废水中的二氯甲烷和1,2-二氯乙烷,检测灵敏度高,有效降低了样品基体的干扰。采用Van Deemter速率方程法对色谱条件进行了研究,对顶空分析条件、盐析剂种类和添加量等进行了探讨,确定了适宜的分析条件为:气化温度为200℃,柱温为95℃,检测器温度为180℃,柱前压为0.11 MPa,顶空平衡温度为60℃,平衡时间为30 min,盐析剂为NaCl且添加量为1 g。在此条件下,方法的检测灵敏度高,线性关系良好,二氯甲烷、1,2-二氯乙烷线性相关系数R2≥0.9998,检出限均小于1μg/L。

In this paper,dichloromethane and 1,2-dichloroethane in maltol production wastewater were determined by salting out combined with headspace gas chromatography to improve the detection sensitivity and reduce the interference of sample matrix.The chromatographic conditions were studied by van Deemter rate equation method.The headspace analysis conditions,the type and amount of salting out agent were discussed.The suitable analysis conditions were determined as follows:The gasification temperature was 200 ℃,column temperature was 95 ℃,detector temperature was 180 ℃,precolumn pressure was 0.11 MPa,headspace equilibrium temperature was 60 ℃ and the equilibrium time was 30 min,The salting out agent was NaCl and the addition amount was 1 g.Under these conditions,the method had high detection sensitivity and good linear relationship,The linear correlation coefficient of dichloromethane and 1,2-dichloroethane were more than 0.9998,and the detection limit was both less than 1 μg/L.