spectrophotometric determination of silver ion in pharmaceutical materials using an organic reagent

A sensitive spectrophotometric method was studied for the determination of silver ion in the presence of several interfering metal ions with high concentrations. this method relies on the formation of a complex between silver and 2-[2-(5-nitrothiazolyl)azo]-4,6-dibromophenol (ntadbrp). the new method was applied to determine the silver content in the metal alloys used in dental amalgam. the detection limit for the silver ion was 0.139 μg/ml, and the range of concentrations following beer’s law was from 1.0 to 50.0 ppm. the average percentage of silver present in the dental fillings was 38.9% with a standard deviation of ±0.01% and a recovery rate of 97%. uv-vis spectrophotometry was used to compare it with the actual percentage of silver in the dental filling material, as indicated by the manufacturer, with no statistically significant differences.