催化动力学分析法测定痕量铅

CATALYTIC DETERMINATION OF TRACE AMOUNTS OF LEAD

本文研究了在H_3BO_3—KCl—NaOH缓冲体系中,铅催化过氧化氢氧化对硝基偶氮苯—α萘酚这一新的指示反应,确定了测定痕量铅的适宜条件,当体系加入DMF后进一步提高了灵敏度。本方法的检出限为6.1×10^(-9)g/mL,测定范围为0.01～0.1/μg/mL,变动系数为4.7％％的。本方法已用于酒样中铅含量的测定,回收率在95％以上。

A new catalytic-spectrophotometric method based on the oxidation of pnitrobenzene-azo-naphthol with hydrogen peroxide in H_3BO_3-KCl-NaOH medium catalyzed by Lead (Ⅱ) is examined. The sensitivity can be raised further when dimethy-formamide is added in the reactive system. The detection limit of the method is 6.1 x10^(-3)μg/mL, the linear range is from 0.02 to 0.1μg/mL, the variation coefficient is 4.7% and the recovery is about 95％. It has been applied for the determination of Lead (Ⅱ) in Wine samples with satisfactory results.