Synthesis of p-Nitrobenzenediazoamido Black 10B and Its Application to Spectrophotometric Determination ofMicro Amount of Cadmium

Abstract

A new azoamino reagent p-nitrobenzenediazoamido black 10B (p-NDABB)

has been synthesized, and found to be a good chromogenic

reagent for cadmium. In pH 9.8 Na₂B₄O₇-NaOH buffer solution cadmium

reacts with p-NDABB to form green chelate (1 : 3), exhibiting an

absorptivity 1.81 x 10⁵ L mol^–1 cm^–1. Beer's law is obeyed in the range

0–9 μg/25 mL Cd(II). The method is simple and rapid, with high sensitivity

and good selectivity and it is applied to the determination of trace amounts

of cadmium in waste water and industrial materials with satisfactory

results.