Abstract
The content of bromine in foodstuff has become a serious problem recently. Weinvestigated the behavior of bromine in the process of salt-making and the equilibrium of bromide ion in heterogeneous system at 75°C was studied. Then, we determined bromide ion and bromate ion in kitchen-salt. The following results were obtained:
1. The concentration of bromide ion in brine and the permselectivity of bromide ion against chloride ion with a new type of ion exchange membrane were slightly increased in comparison with an old type of ion exchange membrane.
2. In the process of concentration the deposition of bromide ion was observed before the deposition of potassium ion. Bromide ion was estimated to exist in the crystal of sodium chloride.
3. The equilibrium of Na+, K+, Mg2+, Ca2+, Cl-, Br--H2O at 75°C was determined, and the resuit indicated that it was unsaturated yet in the case of ordinary concentration of bromide ion in mother liquor (about 1%).
4. The conteats of bromide ion and bromate ion in the kitchen-salts of seven salt-making companies were determined by the modified Kolthoff-Yutzy method. Only bromide ion was contained in all kitchen-salts, and its concentration was 400-700mg/kg. These values were not of a serious problem for food sanitation.
