Determination of Nickel with 2-(2-Quinolylazo)-5-diethylaminoaniline as a Chromogenic Reagent

A sensitive, selective and rapid method for the determination of nickel based on a rapid reaction of nickel(II) with 2-(2-quinolylazo)-5-diethylaminoaniline (QADEAA) has been developed. In the presence of pH = 6.0 ammonia–ammonium chloride buffer solution and sodium dodecyl sulfonate (SDS) medium, QADEAA reacts with nickel to form a violet complex having a molar ratio of 1:2 (nickel to QADEAA). The molar absorptivity of the complex is 1.38 × 105 l mol–1 cm–1 at 595 nm. Beer’s law is obeyed in the range of 0.01–0.4 µg/ml. This method had been applied to the determination of nickel with good results.