4. Conclusions
A fill and flow channel biosensor with a predictor electrode was developed to determine sulfite. The basis of determination
is the current difference between predictor and detector electrodes. This strategy can efficiently correct for the interfering current at the detector electrode. Acceptable repeatability (R.S.D. < 10%) was obtained. The interferences of ethanol, ascorbic acid, sorbic acid and tartaric acid were investigated. Experimental results indicated that the measured
sulfite concentrations were in good agreement with spiked values. Finally, this method was used to determine sulfite in a beer sample. The detected concentrations were compared with values obtained from a reference method
based on the Monier–Williams method.