Carlos Katherine S, de Jager Lowri S
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Dr, HFS 706, College Park, MD 20740.
J AOAC Int. 2017 Nov 1;100(6):1785-1794. doi: 10.5740/jaoacint.17-0033.
Sulfites are added to a wide range of food and beverage products to prevent browning or oxidation. Although most of the population do not experience side effects from consuming sulfites, a small subset has been shown to experience an "allergic-like" response. For this reason, the U.S. Food and Drug Administration requires that sulfites be labeled on all products that contain more than 10 mg/kg (parts per million) sulfur dioxide. The current regulatory method, optimized Monier-Williams (OMW) Official Method 990.28, has been successful in quantifying sulfites in most matrixes, but is time-consuming and has a method detection limit at the regulatory-labeling threshold. Recently, an LC-tandem MS (MS/MS) method was published that was applicable to a wide range of sulfite-containing matrixes. This method converts free and reversibly bound sulfite to the formaldehyde adduct hydroxymethylsulfonate, which could then be separated from matrix constituents using a hydrophilic interaction LC analytical column and subsequently be detected with tandem MS (MS/MS). In this study, multilaboratory validation was conducted with 11 laboratories in the United States and Canada. Four matrixes were spiked at varying concentrations and three additional commercially sulfited matrixes were included. An abbreviated comparison study between the LC-MS/MS and OMW methods was conducted for select samples. Average recoveries for all matrixes ranged from 86 to 114% with RSDr and RSDR values of 4.5-17.5 and 8.6-22.5%, respectively. Further comparisons will be necessary to draw comparisons between the two methods. This method proved to be a faster and more sensitive way to determine sulfites in food and beverages, showing promise for the continuing improvement of enforcement of sulfite labeling requirements to protect individuals who have sulfite sensitivity.
亚硫酸盐被添加到广泛的食品和饮料产品中，以防止褐变或氧化。虽然大多数人在食用亚硫酸盐后不会出现副作用，但一小部分人已被证明会出现“类似过敏”的反应。因此，美国食品药品监督管理局要求在所有含有超过10毫克/千克（百万分之一）二氧化硫的产品上标明亚硫酸盐。目前的监管方法，即优化的莫尼尔-威廉姆斯（OMW）官方方法990.28，已成功地对大多数基质中的亚硫酸盐进行了定量，但耗时较长，且方法检测限处于监管标签阈值。最近，一种液相色谱-串联质谱（MS/MS）方法被发表，该方法适用于广泛的含亚硫酸盐基质。该方法将游离和可逆结合的亚硫酸盐转化为甲醛加合物羟甲基磺酸盐，然后使用亲水相互作用液相色谱分析柱将其与基质成分分离，随后用串联质谱（MS/MS）进行检测。在本研究中，在美国和加拿大的11个实验室进行了多实验室验证。对四种基质以不同浓度进行加标，并纳入另外三种市售亚硫酸盐处理的基质。对选定样品进行了液相色谱-质谱/质谱法和OMW方法之间的简要比较研究。所有基质的平均回收率在86%至114%之间，相对标准偏差（RSDr）值和相对标准偏差（RSDR）值分别为4.5-17.5%和8.6-22.5%。需要进一步比较以对这两种方法进行对比。该方法被证明是一种更快且更灵敏的测定食品和饮料中亚硫酸盐的方法，有望在持续改进亚硫酸盐标签要求的执行方面发挥作用，以保护对亚硫酸盐敏感的个体。
