Abstract:

The optimum reaction conditions for decoloring effect of the blue complex formed between iodine and starch by CN- when the pH of KH₂PO₄-NaOH buffer solution is 7 have been studied. The maximum absorption wavelength of decoloring solution lines at 570 nm with a molor absorptivity of 3.62×104 L/(mol·cm). Beer's law holds within the range of 0-0.8 mg/L ofCN^-，the detection limit is 0.02 mg/L and the recovery rate is in the range of 98.0%-103.5%. The method has been applied to the determination of micro CN- in wastewater with satisfactory results.

Key words: indirect spectrophotometry, iodine, starch, wastewater

摘要：

研究了在pH7.0的KH2PO4-NaOH缓冲溶液中,CN-使碘与淀粉形成的蓝色络合物褪色的最佳反应条件。褪色溶液的最大吸收波长为570nm,表观摩尔吸光系数为3.62×104L/(mol·cm),CN-质量浓度在0∼0.8mg/L范围内符合比耳定律,检出限为0.02mg/L,样品加标回收率为98.0%∼103.5%之间。该法已应用于含氰废水中微量CN-的测定,获得了满意的结果。

关键词: 间接光度法, 碘, 淀粉, 废水

CLC Number: 

• O657.3