Synthesis of 1-(4-Antipyrine)-3-(3-Nitroaniline)-Triazene and its Color Reaction with Mercury(II)

The synthesis of a new triazene reagent 1-(4-antipyrine)-3-( 3-nitroaniline)-triazene (ANTA) and its color 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, ASTA could reacted with Hg ( Ⅱ) to form a red stable complex of which the molar ratio of reagent︰metal was 2︰1 in Na 2 B 4 O 7 -NaOH medium.. The maximum absorption peak of the complex was located at 495 nm with the apparent molar absorption of 3.8 ×10 5 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%.