Selective separation and determination of copper and gold in gold alloy using ion exchange polyurethane foam

A sensitive and selective determination of copper and gold in gold alloys was achieved using a strong anion exchange polyurethane foam (PUFIX) and polyurethane foam after hydrolysis (white-PUF). The total sorption capacity of the resin was 4.22 and 0.85 mmol g(-1) for copper and gold, respectively. The maximum sorption of Cu (II) and An (III) were in 0.02-0.2 and 0.06 M HCl, respectively. The half-life values of sorption t(1/2)) was 2.2 and 0.5 min for Cu (II) and Au (III), respectively. The thermodynamic parameters were also determined. The red color formed on the surface of the white-PUF is used for quantitative and/or serniquantitative determination of trace amounts of copper and gold ions spectrophotometrically or visually, respectively. As low as 4.8 ng cm(-2) of copper and gold is easily detected and Beer's law is obeyed in the concentration range of 0.025-0.21 mu g mL(-1) with molar absorbtivity of 3.5 x 10(4) L mol(-1) cm(-1). PUFIX and white-PUF was verified as a good sorbent by Cu (II) and An (III) determination in gold alloy.