Study of Chromogenic Reaction of p-Acetylchlorophosphonazo with Lead(II)

摘要

In this work, p-acety Ichlorophosphonazo (CPApA) and lead(II) form a blue complex in a pH 3.5 CH3COOH-CH3COONa buffer solution. A new method has been established for the determination of lead by spectrophotometry: The maximum absorption peak of Pb(II)-CPApA complex locates at 606 am. The absorbance is linearly related over the range of 0.1-4.6 μg mL~(-1) at the wavelength. The apparent molar absorptivity of method ε_(606 nm) = 2.56 x 10~4 L mol~(-1) cm~(-1). The method has been used to determine lead in potato. The relative standard deviation was 1.05-2.05 % for thirteen replicate determdnations. The recovery of the standard addition was 99.1-105.0 %.