流动注射-分光光度法测量总氰化物的研究

Determination of Total Cyanide by Flow Injection Spectrophotometry

通过流动注射分析仪实验,检验水中总氰化物,在酸性条件下,样品经140℃高温高压水解及紫外消解,释放出的氰化氢气体被氢氧化钠溶液吸收。吸收液中的氰化物于氯胺T反应生成氯化氰,然后与异烟酸反应水解生成戊稀二醛,再与巴比妥酸作用生成蓝紫色化合物,于600 nm波长处测量吸光度,根据测定结果分析仪器方法的标准曲线相关系数,分析仪器方法检出限、精密度、准确度。实验结果表明,流动注射分析仪在测量水中总氰化物时,总氰化物质量浓度在0.0~200.0μg/L范围内线性关系良好;流动注射分析法测定总氰化物的检出限为0.8μg/L,低于标准方法检出限0.001 mg/L;流动注射-分光光度法测定总氰化物精密度在1.11%~1.92%之间,满足标准方法要求的小于20%;有证标准样品测试中,测定相对误差分别为5.31%和4.16%,在实际样品加标测试中,加标回收率在96.1%~103%之间,能满足标准方法要求。因此,流动注射-分光光度法测定总氰化物能够满足常规水体中总氰化物的检测要求。

The total cyanide in water was tested by flow injection analyzer.Under acidic conditions,the sample was hydrolyzed at 140℃under high temperature and high pressure and digested by UV,and the released hydrogen cyanide gas was absorbed by sodium hydroxide solution.Cyanide in the absorption solution reacts with chloramine T to produce cyanogen chloride,then reacts with isonicotinic acid to hydrolyze to produce amyl dialdehyde,and reacts with barbituric acid to produce blue purple compound.Measure the absorbance at the wavelength of 600 nm,analyze the correlation number of the standard curve of the instrument method according to the determination results,and analyze the detection limit,precision and accuracy of the instrument method.The experimental results show that the concentration of total cyanide in water measured by flow injection analyzer is 0.0~200.0μg/L;The detection limit of total cyanide by flow injection analysis is 0.8μg/L,0.001 mg/Llower than the detection limit of the standard method;The precision of determination of total cyanide by flow injection spectrophotometry is between 1.11%~1.92%,and less than 20%meets the requirements of the standard method;In the test of certified standard samples,the relative errors were 5.31%and 4.16%respectively,;In the actual sample spiked test,the spiked recovery is 96.1%~103%,which can meet the requirements of the standard method.Therefore,the determination of total cyanide by flow injection spectrophotometry can meet the detection requirements of total cyanide in conventional water.