中文摘要：

在氨水介质中，痕量Cu（Ⅱ）对H2O2氧化茜素红S的褪色反应具有催化作用，而Pb（Ⅱ）对此褪色反应具有明显的阻抑作用，由此建立了测定痕量Pb（Ⅱ）的新催化动力学光度法。应用正交试验法确定了反应的最佳条件，测定了有关动力学参数。方法的检出限为7．5ng/mL，线性范围为0．0～0．35μg／mL，并应用于皮蛋和茶叶样品中Pb（Ⅱ）含量的测定，同时还探讨了阻抑反应机理。

英文摘要：

It was found that lead（ Ⅱ ） could sensitively inhibit the reaction of hydrogen peroxide oxidizing discoloration of alizarian S catalyzed by copper（ Ⅱ ） in NH3·H2O solution. A new inhibition-catalysis kinetic spectrophotometry for the detennination of lead（ Ⅱ ） was proposed. Experimental conditions were optimized by orthogonal test and the kinetic parameters were calculated. The detection limit of the method is 7.5 ng/mL, and the linear range is 0 ～ 0. 35 μg/mL. This method has been successfully applied to the determination of lead（Ⅱ ） in preserved eggs and tea. The mechanism of inhibition reaction was also discussed.