水中氰化物连续流动注射分析的改进

Modified method for determination of cyanide in water by flow injection analysis

目的通过对现有方法进行改进,建立灵敏、稳定、准确地测定水中氰化物的连续流动注射分析方法。方法用LACHAT QC8500流动注射分析仪,在改进的120℃蒸馏温度和85℃显色温度条件下在线蒸馏,测定水中氰化物。结果在改进的实验条件下,氰化物浓度在0.50-100μg/L范围内具有良好的线性关系（r=0.999 9）,最低检出限为0.25μg/L,RSD为1.2%-5.3%,平均回收率为91.4%-100.3%。结论改进后的方法快速、灵敏度高、重现性好、结果准确,适用于水中氰化物的测定。

Objective To establish a modified method of flow injection analysis（FIA） sensitive, stable and accurate for the determination of cyanide in water. Methods Under the improved condition of distillation at 120 ℃ and color reaction at 85℃,the cyanide in water was determined by on-line distillation with LACHAT QC8500 FIA. Results Under the improved conditions, cyanide concentration showed a good linear relationship（r =0.9999） in the range of 0.50-100 μg/L, the limit of detection was 0.25 μg/L, the relative standard deviation ranged from 1.2% to 5.3% and the average recovery with standard addition was from 91.4% to 100.3%. Conclusion The modified method is rapid, sensitive, accurate and applicable to the determination of cyanide in water