Photochemical reaction between ascorbic acid and silver (I) in aqueous Triton X-100 and its analytical application

A new spectrophotometric method for ascorbic acid determination has been described. Colourless silver (I) is photochemically reduced in Triton X -100 (TX -100) medium by ascorbic acid to yellow silver sol having particles with nanometer range size. The particles show a surface plasmon absorption band at 415 nm with molar absorptivity 1.43 x 10(4) lit mol(-1) cm(-1) and the Sandell sensitivity of 1.23 x 10(-2) mu g cm(-2). The determination is possible in the range of 0-13 ppm of ascorbic acid. The limit of detection is 0.4 ppm. The relative standard deviation is < +/-5% for all determinations and the confidence limit for 7.50 ppm of;ascorbic acid (10 determinations, 95%) is 7.84+/-0.32. Statistical parameters, effects of TX-100 concentration, irradiation time and interferents are studied. The method is simple, quick and suitable for vitamin C analysis in pharmaceutical preparations.