Synthesis of 1-(4-antipyrine)-3-(sulfanilic acid)-triazene and its color reaction with mercury II

The synthesis of a new triazene reagent 1-(4-antipyrine)-3-(sulfanilic acid)-triazene(ASTA) and its color reaction with HgⅡ was studied and a new spectrophotometric method for the determination of Hg was established.The results showed that in the presence of micromulsion Tween-80,ASTA could react with HgⅡ to form a red stable complex with molar ratio of 2∶1 in Na2B4O7-NaOH medium.The maximum absorption peak of the complex was located at 488 nm with the apparent molar absorptivity of 1.7 ×105 L·mol-1·cm-1.Beer′s law was obeyed in the range of 0.5-15 μg/10 mL for HgⅡ and detection limit was 0.16 mg/L.This method has been applied to the determination of HgⅡ in lead-zinc ore samples,and the results were in accordance with those obtained by AAS method with recoveries about 104 % and RSD(n=6) not more than 4.4 %.