DEVELOPMENT OF RAPID SULFURDIOXIDE D ECTION EQUIPMENT FOR FOOD SAF Y PURPOSE

摘要

The coulometric titration technique was developed for determination of sulfur dioxide in food and beverages. Sulfur dioxide, which presented in food and beverages in the form of bisulfite and sulfite, reacts with iodine generated from iodide at working electrode. An optimum condition for iodine generation was 10 mA of electric current in 0.1 M KI solution. The amount of sulfur dioxide in the samples could be obtained by direct calculation from the quantity of electric current used in titration or from a generation time of iodine in reaction. The whole process of sulfur dioxide detection by this technique took only 1 - 3 minutes, whereas the A.O.A.C. method using distillation and titration processes took more than 1 hour. The accuracy and precision of the modified technique for sulfur dioxide detection in food and beverages were high and comparable to the A.O.A.C. method (p<0.05) at the concentration of sulfur dioxide between 0 - 350 ppm.