Kim H J
U.S. Army Natick Research, Development and Engineering Center, MA 01760.
J Assoc Off Anal Chem. 1990 Mar-Apr;73(2):216-22.
A liquid chromatographic (LC) method for determination of total sulfite in foods and beverages by alkali extraction followed by ion exclusion chromatographic separation and electrochemical detection (IEC-EC) was collaboratively studied by 9 laboratories. Blind duplicate samples of starch, diluted lemon juice, wine cooler, dehydrated seafood, and instant mashed potatoes were analyzed without spiking and with added sulfite at 2 levels. The initial sulfite levels varied from 0 to 384 ppm SO2, and the levels added varied from 10 to 400 ppm. The initial sulfite levels determined by the IEC-EC method and the Monier-Williams method were in good agreement. Recovery of added sulfite by the IEC-EC method was generally higher than that by the Monier-Williams method. Within-laboratory repeatability (RSDr) for the IEC-EC method varied from 4.4 to 26.0%, and overall reproducibility (RSDR) varied from 8.5 to 39.3%. The collaborators found the method to be fast, sensitive, and easy to use, which makes it a useful alternative to the Monier-Williams method. The method has been adopted official first action.
9个实验室共同研究了一种液相色谱（LC）法，该方法通过碱提取、离子排斥色谱分离和电化学检测（IEC-EC）来测定食品和饮料中的总亚硫酸盐。对淀粉、稀释柠檬汁、果味葡萄酒、脱水海产品和速溶土豆泥的盲样进行了双份分析，一份未加标，另一份添加了2个水平的亚硫酸盐。初始亚硫酸盐水平在0至384 ppm SO₂之间，添加水平在10至400 ppm之间。通过IEC-EC法和莫尼尔-威廉姆斯法测定的初始亚硫酸盐水平吻合良好。IEC-EC法对添加亚硫酸盐的回收率通常高于莫尼尔-威廉姆斯法。IEC-EC法的实验室内重复性（RSDr）在4.4%至26.0%之间，总体再现性（RSDR）在8.5%至39.3%之间。协作实验室发现该方法快速、灵敏且易于使用，是莫尼尔-威廉姆斯法的一种有用替代方法。该方法已被采用为官方首次行动方法。
