Trifluoroethylxanthate as a reagent for the determination of gold

Abstract

A direct spectrophotometric method has been developed for the determination of gold using trifluoroethylxanthate as the complexing agent. Gold(III) reacts with this reagent in the ratio 1 : 3 (metal to ligand) over the pH range 2.0–11.0. The complex absorbs strongly at 452 nm and Beer's law is obeyed over the concentration range 1.3–7.5 p.p.m. of gold. The molar absorptivity and Sandell's sensitivity are 1.09 × 10³ 1 mol^–1 cm^–1 and 0.018 µg cm^–2 of Au, respectively. Ten replicate determinations of 45 µg of gold gave a mean absorbance of 0.250 with a standard deviation of 1.66 × 10^–3 and a relative standard deviation of 0.66%. The interference of various ions has been studied and conditions were developed for the determination of gold in certain synthetic samples.