含硫化物、硫氰酸盐水质中易释放氰化物测定方法研究

Methods for WAD cyanide determination in water containing sulfide and thiocyanate

研究建立了含硫化物、硫氰酸盐水质中易释放氰化物的测定方法,采用硝酸银作为掩蔽剂,同时结合两次蒸馏去除硫化物、硫氰酸盐的干扰,馏出液采用氢氧化钠溶液吸收。对于氰化物质量浓度较高的样品采用硝酸银滴定法测定,氰化物质量浓度低的样品采用异烟酸-吡唑啉酮法测定。该方法测定结果的相对标准偏差为0.51%~3.51%,加标回收率为95.6%~104.2%,具有操作简单、成本低和准确度高的优点。

The determination methods for WAD cyanide in water with sulfide and thiocyanate content are established in the study.Silver nitrate is used as masking agent to eliminate the interference of sulfide and thiocyanate with the help of twice distillation.The distilled solution is absorbed with sodium hydroxide.Silver nitrate titration method is used to determine the samples with higher WAD cyanide mass concentration,while isonicotinic acid-pyrazolone methed is used to determine the samples with lower WAD cyanide mass concentration.The RSD of the determination results using this method is 0.51%-3.51%,and the recovery rate of reference materials is 95.6%-104.2%.The method is easy to operate,low-cost and accurate.