Synthesis of a New Reagent 1-(4-Antipyrine)-3-(3-nitroaniline)triazene and Its Colour Reaction with Mercury(II)

Abstract

In this work, a new reagent 1-(4-antipyrine)-3-(3-nitroaniline)triazene and its colour reaction with Hg(II) was studied and a new spectrophotometric method for the determination of Hg(II) was established. The results showed that in the presence of micromulsion Tween-80, 1-(4-antipyrine)- 3-(3-nitroaniline)triazene could reacted with Hg(II) to form a red stable complex of which the molar ratio of reagent:metal was 2:1 in Na₂B₄O₇-NaOH medium. The maximum absorption peak of the complex was located at 495 nm with the apparent molar absorption of 3.8 × 10⁵ L mol^-1 cm^-1. Beer’s law was obeyed in the range of 0.32-10 μg/10 mL for Hg(II) and the detection limit was 0.10 mg/L. Many ions did not interfere the colour reaction system due to the existence of ammonia. This method was applied to determination of Hg(II) in lead-zinc ore samples and the results were in accordance with those obtained by AAS method. Recovery was in the range of 103.0-103.2 % and the RSD (n = 6) was not more than 4.6 %.