Abstract: A new method based on the principle of titrating with iodine after distilling (GB/T5009.34-1996) was presented. Micro-titrating with iodine after macro-distilling, was used to determine SO2 residue on refined konjac flour. The results of the two methods were 2.055g/kg, and 2.051g/kg, respectively. Their variance coefficients were 0.16%, 0.18%, respectively. There was remarkable difference between the two methods. The method, micro-titrating with iodine after macro-distilling, had better advantages, for example, with smaller amount consumption of sample and reagent, shorter analytical time, reduced cost, and so on. It should be a good analytical method.

Key words: micro-titration, determination, refined konjac flour, SO2