SOLID-PHASE SPECTROPHOTOMETRIC MICRODETERMINATION OF COPPER

A method for the determination of microgram per litre level of copper has been developed, based on Solid-Phase Spectrophotometry (SPS). Copper reacts with bichinconinic acid to form a 1:2 anionic reddish purple of Cu(I), which is fixed on a dextran-type anion-exchange resin. Resin phase absorbance is measured directly and allows for the determination of copper within the range of 1-20-mu-g.l-1, using a 2,000 ml sample with an RSD of 1.7%. The method has been used in the determination of copper in natural waters.