Spectrophotometric Determination of Copper in Metallic Alloy Using a Bidithiolene: A Comparative Study

摘要

A novel and sensitive spectrophotometric method for the determination of copper in the presence of high concentrations of interfering ions was studied. The new method, based on the complex formed between copper and 4,5-dimercapto-1,3-dithyol-2-tionate, was applied to the determination of copper in metallic 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 of concentrations that follow 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 standard deviation of +-0.76% and recovery of 97.5%. The spectrophotometric method using cuproin and atomic absorption spectrometry was employed for comparison purposes, and no significant differences were observed among the methods.