比色法测定水中微量三氯杀螨醇

Colorimetric Determination of Dicofol in Water

使用比色法测定水中微量三氯杀螨醇的浓度。首先用正己烷萃取浓缩水中的三氯杀螨醇,比较了加入不同量的去离子水,不同浓度、不同量的NaOH,不同的反应显色温度和反应时间以及吡啶用量等对体系吸光度的影响。得出最佳的显色条件：0.2ml去离子水,0.1ml质量浓度为45%的NaOH溶液,与2.0ml吡啶混合,于100℃水浴中反应3.0min,反应液在4000r/min离心2.0min,取出反应液在530nm处测定吸光度值。此方法的标准工作曲线相关系数为0.9914,方法的绝对检出限为0.2μg三氯杀螨醇。样品加标回收率为83.7%~114.1%,相对标准偏差小于10%。

The concentration of dicofol in water was determined using colorimetric determination method.Dicofol in water was first of all extracted and concentrated by n-hexane.Reaction conditions including dosage of de-ionized water,the dosage and concentration of NaOH,heating temperature and time,the dosage of pyridine were researched.The result showed that 0.2ml de-ionized water,0.1ml 45% NaOH and 2.0ml pyridine,3.0min heating time under 100℃ water bath are optimal conditions.Absorbency was determined at 530nm.the detection limit is 0.2μg dicofol by this method.Recoveries are between 83.7 and 114.1%,and RSD is less than 10%.