微孔膜气体扩散分离流动注射光度法测定废水中氰化物

Spectrophotometric Determination of Cyanide in Waste Water in a Flow Injection Analysis System With Gas-diffusion Separation

研究了利用吡啶-巴比妥酸显色体系反应的中间产物,采用微孔膜气体扩散分离流动注射分析技术测定工业废水中氰化物,该法具有简便、快速并能消除某些干扰的特点。进样频率为65个样/h,检出限为0.02μg/ml,取氰化物2.5μg/ml时测量的相对标准偏差为0.3％(n=20),测定实际样品结果令人满意。

An automaatic flow injection analysis system with gas-diffusion separation and spectrophotometric detection is described for the determination of cyanide in industrial waste waters. An unstable pink colour intermediate product of the reaction of cyanide with pyridine-barhituric acid is used instead of the conventional blue-violet final product to improve the efficiency. The detection limit of the method was 0. 02 fig/ml and relative standard deviation was 0. 3% (n=20). The calibration graph was linear over the range of 0. 1-18 fig/ml for cyanide and the sampling rate was 65/h. The proposed method has been applied to the determination of cyanide in industrial waste waters with satisfactory results.