无汞吸收法测白糖中亚硫酸盐

Sulfite Determination in Sugar with Non-mercury Absorption Treatment

食品中亚硫酸盐的测定方法用的是四氯汞钠-副玫瑰苯胺法,四氯汞钠溶液为剧毒药品,对人和周围环境造成的污染较难消除,而且用四氯汞钠溶液配制的SO2标准溶液需放置过夜后才能使用,浓度又极易变化,每次试验都需标定,增加了试验时间,改为甲醛吸收-副玫瑰苯胺法后,由于甲醛使用浓度较低,仅为0.02%,毒性相对较弱,所以对人体和环境危害也较小,用甲醛吸收液配制的标准溶液也相对稳定,经大量试验,标准曲线线性达到0.9999,样品白糖加标回收率达到94%以上。用甲醛吸收-副玫瑰苯胺法测定食品中的亚硫酸盐,既减少了污染,又提高了工作效率和方法的准确度。

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 FAPRA method not only reduces pollution but also improves work efficiency and accuracy.