DETERMINATION OF COPPER AND ARSENIC IN REFINED BEET SUGAR BY STRIPPING VOLTAMMETRY WITHOUT SAMPLE PRETREATMENT

Copper and arsenic have been analysed in refined beet sugar at the mu g kg(-1) level by anodic stripping voltammetry (copper) and cathodic s tripping voltammetry (arsenic) in the differential-pulse mode (DPASV a nd DPCSV) at a hanging mercury drop electrode (HMDE). DPCSV measuremen ts of arsenic are based on its accumulation onto the HMDE as an interm etallic Cu-As compound followed by the reduction of As-0 to arsine in hydrochloric acid medium. Measurements mere directly carried out on un treated sugar solutions. The performance of the procedures was compare d with electrothermal atomic absorption spectrometry and stripping vol tammetry applied to digested sugar samples, and showed in general bett er accuracy. The procedures were applied to the determination of these toxic elements in commercial beet sugar samples and concentrations be low 50 mu g kg(-1) copper and 15 mu g kg(-1) arsenic were found, which are much lower that those allowed by the current regulations.