Spectrophotometric determination of silver through photochemical formation of silver sol using diphenylamine in aqueous triton X-100 medium

Silver(I) is transformed into yellow coloured silver sol (lambda(max) = 420 nm; epsilon = 0.98 x 10(4) l mol(-1) cm(-1)) in aqueous Triton X-100 medium by photochemical reaction with diphenylamine. This has been used as a basis for the spectrophotometric determination of silver(I) in the lower parts per million (ppm) range in a quick, simple and reliable way. Beer's law is obeyed in the range of 0-8.5 ppm of silver. The relative standard deviation and confidence limit (95%) for 5.65 ppm of silver (10 replicates) are found to be +/- 1.8% and 6.00 +/- 0.07 respectively. The Sandell sensitivity was 1.1 x 10(-2) mu g cm(-2). The effects of irradiation time, Triton X-100 concentration and the presence of interfering substances are discussed. The method is applied for the determination of silver in photographic print paper.