CATALYTIC DETERMINATION OF COPPER IN BLOOD-PLASMA USING FLOW-INJECTION BIAMPEROMETRY

A method for the determination of copper based on the catalytic effect of Cu(II) on the oxidation of thiosulphate by Fe(III) is described. F e(II) formed in this reactiton in the presence of an excess of Fe(III) allows the use of amperometric detection with two polarized platinum wire electrodes. At a polarizing voltage of 80 mV a linear dependence of current intensity on Cu(II) concentration is obtained in the range of Cu(II) concentrations present in blood plasma. In determinations wi th a sampling rate of 70 h-1 a satisfactory agreement was obtained bet ween the results of flow-injection analysis with biamperometric detect ion and flame atomic absorption spectrometry.