Abstract: According to international standards, the determination measure of the food sulfite by means of the Sodium tetrachloromercurate-Pararosaniline(ST-PRA)method. But the ST solution is an extremely toxic drug, a pollutant hardly possible to be removed. Besides, the SO2 standard solution compounded ST solution can not be used until over night, yet the concentration of SO2 standard solution is changeable, so that the calibration should be repeated in every test, or a waste of time. In this article, the formaldehyde absorption- Pararosaniline (FA-PRA), instead of ST-PRA was introduced. Because the formaldehude at 0.02% low concentration, only a weak toxin could be formed with much less damage to human and environment. The calibration curve quality is up to 0.9999 and the recoveries of white sugar reach 94%. The determination of the sulfite by FA- PRA method not only reduces pollution but also improves work efficiency and accuracy.

Key words: sulfite, sulfur dioxide, sodium tetrachloromercurate, formaldehyde, pararosaniline