Holak W, Patel B
J Assoc Off Anal Chem. 1987 May-Jun;70(3):572-8.
A differential pulse polarographic (DPP) method for the determination of "free" and "total" sulfite in foods was collaboratively studied by 8 laboratories. The collaborators analyzed blind duplicate samples of shrimp, orange juice, peas, dried apricots, and dehydrated potatoes. Collaborators also analyzed the same samples spiked with sulfites at 2 levels, which ranged from 10 to 1100 micrograms added SO2/g. The variability of free SO2 results was excessive for quantitative analysis, but the method can be used for qualitative detection of free SO2. The method for total SO2 determination was suitable for as low as approximately 10 micrograms/g. Recoveries are comparable to those for the official Monier-Williams method at high levels and are superior at low levels. The method has been adopted official first action for determination of total SO2 in the foods studied.
8个实验室对一种用于测定食品中“游离”和“总”亚硫酸盐的微分脉冲极谱法（DPP）进行了协同研究。研究人员分析了虾、橙汁、豌豆、杏干和脱水土豆的双盲重复样品。研究人员还分析了添加了两种不同水平亚硫酸盐的相同样品，添加的二氧化硫含量范围为10至1100微克/克。游离二氧化硫结果的变异性过大，无法进行定量分析，但该方法可用于游离二氧化硫的定性检测。总二氧化硫的测定方法适用于低至约10微克/克的含量。在高水平时，回收率与官方的莫尼尔-威廉姆斯方法相当，在低水平时则更优。该方法已被首次作为官方方法用于测定所研究食品中的总二氧化硫。
