5-Br-PADAP和铜(Ⅱ)显色反应的双波长分光光度法研究

STADY OF COLOR REACTION BETWEEN 5-Br-PADAP AND COPPER(Ⅱ) OF DUAL- WAVELENGTH SPECTROPHOTOMETRY

应用双波长分光光度法研究了在pH 3 .6的缓冲溶液中铜 (Ⅱ )与 5 -Br-PADAP和Tween- 80形成三元胶束配合物的显色反应 .结果表明 ,可用双峰双波长法测定微量铜 (Ⅱ ) ,该法具有很高的灵敏度 ,ε=1 .0 3× 1 0 5L·mol-1 ·cm-1 ,铜 (Ⅱ )浓度在 0～ 0 .8mg·L-1范围内符合比尔定律 .用于粮食中微量铜 (Ⅱ)的测定 ,结果比较满意 .

Using dual wavelength spectrophotometry,this paper studied the color reaction that under the buffer medium of pH?3.6 and the presence of Tween-80,copper(Ⅱ) forms ternary micellar complex with the 5-Br-PADAP.The result shows that the trace copper(Ⅱ) can be determined by dual peak and dual wavelength spectrophotometry,and this method has high sensitivity,the apparent molar absorption coefficient is 1.03×10 5?L·mol -1 ·cm -1 .Beers law is obeyed by copper(Ⅱ) in the range of 0～0.8?mg·L -1 .This method can be applied in determination of trace copper(Ⅱ) in the grain sample and the result of which is quite satisfactory.