7-碘-8-羟基喹啉-5-磺酸体系分光光度法测定水样中铜的含量

Spectrophotometric Determination of Copper in Water Using 7-Iodo-8-Hydroxyquinoline-5-Sulfonic Acid System

研究了7-碘-8-羟基喹啉-5-磺酸与铜(Ⅱ)的显色反应。在pH=5.0Clark-Lubs缓冲介质中,铜(II)与7-碘-8-羟基喹啉-5-磺酸形成黄色络合物,其最大吸收波长位于380nm处,表观摩尔吸光系数为7.35×103L.mol-1.cm-1,铜(II)的含量在0.15—4.5μg/mL范围内符合比耳定律,线性回归方程为A=0.1122x(μg/mL)+0.0079,相关系数0.9999。方法用于合成水样中微量铜的测定,回收率为99%—110%,结果满意。

The color reaction of Cu（Ⅱ） with 7-iodo-8-hydroxyquinoline-5-sulfonic acid takes palce and forms a complex in pH = 5.0 Clark-Lubs buffer solution. The apparent molar absorptivity of this chelate is 7.35 × 10^3L . mol^-1 . cm^-1 at 380nm. Beer＇s law is obeyed in the range of 0. 15- 4.5ug/mL for Cu （Ⅱ）. The linear equation is A = 0. 0079 %- 0. 1122x （ug/mL）, r= 0. 9999. The method is applied to the determination of Cu（Ⅱ） in water with satisfactory results.