Spectrophotometric determination of copper in metallic alloy using a bidithiolene: A comparative study

A novel and sensitive spectrophotometric method for the determination of co pper in the presence of high concentrations of interfering ions was studied . The new method, based on the complex formed between copper and 4,5-dimerc apto-1,3-dithyol-2-tionate, was applied to the determination of copper in m etallic alloys used in dental amalgams with high amounts of tin and silver. The lowest copper concentration detectable was 64 mu g L-1 and the range o f concentrations that fellow Beer's Law was 0.350 to 1.06 mu g mL(-1). The average copper concentration found in metallic amalgams was 10.54% with a s tandard deviation of +/-0.76% and recovery of 97.5%. The spectrophotometric method using cuproin and atomic absorption spectrometry was employed for c omparison purposes, and no significant differences were observed among the methods. (C) 1999 Academic Press.