FACILE PHOTOMETRIC DETERMINATION OF SILVER WITH 2,4,5,7-TETRAIODOFLUORESCEIN STABILIZED WITH STARCH

Abstract

Simple photometric determination of silver was developped. The determination incorporated 2,4,5,7-tetraiodofl uorescein (erythrosine) as chromogenic reagent to form positive colloid with silver ion, not ion associate as
initially assume. The colloid was then stabilized with starch and this ternary system erythrosine-silver-starch was
applied as basis in determination of trace amount of silver (0–6 μg/ml). The developped method was successfully
applied to determine silver in three synthetic samples and came with accuracy > 96.87% after compared to atomic
absorption spectrophotometry (AAS) results and reproducibility < 8.8%.