Study on the color reaction of 1-azobenzene-3-(5-cyano-2-pyridyl)-triazene with silver

The synthesis of a new reagent 1-azobenzene-3-(5-cyano-2-pyridyl)-triazene(ABCPDT) and its colour reaction with Silver have been discussed in this paper. In the buffer solution of Na_2B_4O_7-NaOH(pH 10.0) containing surfactant Triton X-100,the chromogenic reagent reacts with silver to form a complex with molar ratio of 1∶1.This compound has a maximum absorption peak at 550nm,The apparent molar absorptivity is 1.65×10~5 L·mol~(-1)·cm~(-1).Beer′s law is obeyed over the concentration range of 0～12 μg/25 mL for silver.The method has been employed to determine the trace amounts of silver in photographic waste solutions with satisfactory results.