正己烷萃取–连续流动光度法测定含油废水中的氰化物

Determination of Cyanide in Oily Wastewater by Hexane Extraction and Continuous Flow Spectrophotometry

建立在线蒸馏-连续流动分析仪检测含油废水中氰化物的分析方法。水样在pH〉12的碱性条件下，以正己烷为萃取溶剂两次萃取净化，去除废水中的油类干扰物。氰化物的质量浓度在0．005-0．500mg／L范围内与响应峰高呈良好的线性，线性相关系数大于0．999，检出限为0．0009mg／L；对水样进行4个质量浓度水平的加标回收试验，回收率在85．0％～110．0％之间，测定结果的相对标准偏差为2.3％-5．6％（n=6）。该方法样品前处理简单、重现性好、检出限低，适用于含油废水中氰化物的测定。

The distillation on-line continuous flow spectrophotometric method for the determination of cyanide in oily wastewater was established. Under the condition ofpH〉12, the wastewater samples were extracted with hexane twice and cyanide from aqueous phase was measured by continuous flow analyzer. The mass concentration of cyanide was linear with corresponding peak height in the range of 0.005-0.500 mg/L, the correlation coefficient was more than 0.999. The detection limit of the method （LOD） was 0.000 9 mg / L. The recoveries of the target compound ranged from 85.0% to 110.0% and the relative standard deviations was 2.3%-5.6% （n=6）. The method has good reproducibility, lower detection limit, the pretreatment is simple, so it is suitable for the determination of cyanide in oily wastewater.