Synthesis of p-Azobenzenediazoaminoazobbnzene Sulfonic Acid and its Application for Spectrophotometric Determination of Cadmium

Abstract

The synthesis and characteristics of a new chromogenic reagent p-azobenzenediazoaminoazobenzene sulfonic acid (ADAAS) is reported. ADAAS forms a dark-violet red complex with cadmium in the presence of Triton X-100 and in ammonia medium. The molar absorptivity of the complex is 2.02×10⁵ 1 mol⁻¹ cm⁻¹ at 532 nm, and the formation constant of the complex is 6×10²¹ Beer's law is obeyed for cadmium concentrations of between 3.6×10⁻⁸ M and 4.3×10⁻⁶ M. The effect of foreign ion can been eliminated completely by use of masking agents. The proposed method has been used for the determination of trace amounts of cadmium in water samples.

Key Words:

• Synthesis
• p-Azobenzenediazoaminoazobenzene sulfonic acid
• Cadmium
• Spectrophotometry