【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。更多还原

【Abstract】 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 determination 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.更多还原