Spectrophotometric determination of silver with 2-(2-quinolylazo)-5-diethylaminoaniline

A new chromogenic reagent, 2-(2-quinolylazo)-5-diethylaminoaniline (QADEAA) was synthesized. A highly sensitive, selective and rapid method for the determination of silver based on the rapid reaction of silver (1) with QADEAA has been developed. In the presence of sodium citrate-sodium, hydroxide buffer solution (pH 6.5) and sodium dodecyl sulfonate (SDS) medium, QADEAA reacts with silver to form a violet complex of molar ratio 11 (silver to QADEAA). The molar absorptivity of the complex is 1.39 x 105 1 Mol(-1) cm(-1) at 580 nm. Beer's law is obeyed in the range of 0.01-0.6 mug ml(-1). The relative standard deviation for I I replicate samples of 0.2 mug ml(-1) is 1.67%. This method can be applied to the determination of silver in water with satisfactory results. (C) 2002 Elsevier Science B.V. All rights reserved.