STRIPPING POTENTIOMETRIC MEASUREMENTS OF COPPER IN BLOOD USING GOLD MICROELECTRODES

A rapid, reliable, sensitive and simple stripping potentiometric method for the determination of copper in blood samples, based on a bare (mercury-free) gold fiber microelectrode is described. The method involved a 1:40 dilution of the 50 mu l whole blood sample with 0.8 M hydrochloric acid, a short (60 s) deposition at -0.40 V, and a constant stripping current of 0.5 mu A. The analytical performance is not compromised by replacing the traditional mercury electrodes with the gold microsensor The detection limit is 1.5 mu g/l (1 min deposition) and the relative standard deviation for 80 repetitive blood assays is 4.1%. Good agreement with target reference values and flame atomic absorption measurements is reported for both whole blood and blood serum samples, indicating that the total copper content is being monitored. By obviating the needs for mercury plating or disposal, solution stirring, oxygen removal or sample pretreatment, the prospects for on-site monitoring of blood copper levels are greatly improved.