在HAc-NaAe缓冲体系中,痕量铬(Ⅵ)对过氧化氢氧化吡咯红Y的氧化还原反应有催化作用,使吡咯红Y荧光减弱,据此建立了催化荧光法测定痕量铬(Ⅵ)的新方法,同时考察了该催化反应的最优条件及动力学性质。该方法的表观活化能为159.92kJ·mol^-1,反应速率常量为5.7×10^-2s^-1,检测限为0.012μg·mL^-1,测定线性范围为0.02~0.24μg·mL^-1.该方法用于对河水、工业废水及电镀废水中铬(Ⅵ)的测定,结果令人满意。
A simple and highly sensitive new kinetic catalytic fluorimetrie method was proposed for the determination of trace chromium (Ⅵ), based on the catalytic effect of trace amounts of chromium ( Ⅵ ) on the oxidation of Pyronine Y by hydrogen peroxide in acetic acid-sodium acetate buffer medium leading to a decrease in the fluorescence intensity. The optimum conditions and kinetic properties of the catalytic reaction were also studied. The apparent activation energy and the apparent rate constant are 159. 92 kJ·mol^-1 and 5. 7× 10^-2 s^-1 respectively. The linear range of the calibration curve is 0. 02-0. 24 μg ·mL^-1 and the detection limit is 0. 012μg·mL^-1. The present method was applied to the determination of chromium(Ⅵ ) in river water, and industrial and electroplating waste water with good results.