DETERMINATION OF MERCURY AND COPPER TRACES IN ULTRAPURE SPECTRAL CARBON BY DPASV ON A GOLD-FIBER MICROELECTRODE

A simple and sensitive method is proposed applying a gold fibre microelectrode for the DPASV determination of Hg and Cu traces in an ultrapure spectral carbon. The procedure allows simultaneous determination of both elements at the purity level lower than 1 . 10(-6) wt.%. Two different sample preparation techniques - ashing in stream of oxygen, and elution with a mixture of concentrated HCl and HNO3 - were applied for releasing the metals spread in carbon matrix. Testing of the digestion techniques with synthetic Hg and Cu spiked samples proved both to be satisfactory. The proposed determination has a sensitivity high enough to verify the required highest purity level of the spectral carbon as concerns Hg and Cu traces.