PHOTOINITIATED GOLD SOL GENERATION IN AQUEOUS TRITON X-100 AND ITS ANALYTICAL APPLICATION FOR SPECTROPHOTOMETRIC DETERMINATION OF GOLD

Gold complex, HAuCl4 has been transformed into pink-coloured stable go ld sol having lambda(max) at 523 nm (epsilon = 3.06 x 10(3)l . mol(-1) cm(-1)) at room temperature in aqueous Triton X-100 (TX-100) upon phot oirradiation. It is a very rapid and simple process and the absorbance at 523 nm is a direct measure of gold concentration. Beer's law is ob eyed in the range of 0-150 ppm of gold. The relative standard deviatio n for 22.7 and 90.9 ppm of gold are 2.8 and 2.5% respectively. The 95% confidence limit (ten determinations) for 22.7 ppm of gold is 23.6 +/ - 0.5 ppm. Sandell sensitivity is 6.44 x 10(-2) mu g cm(-2). TX-100 ac ts both as a reducing agent and a stabilizer here. Statistical paramet ers, effects of TX-100 concentration, irradiation time and interferent s are studied. The method is applicable for ore and synthetic mixture analysis. (C) 1998 Elsevier Science B.V. All rights reserved.