González Mónica, Gallego Mercedes, Valcárcel Miguel
Department of Analytical Chemistry, Campus de Rabanales, University of Córdoba, E-14071 Cordoba, Spain.
Anal Chem. 2003 Feb 1;75(3):685-93. doi: 10.1021/ac020468f.
A simple and novel screening method for food colorants was proposed. Synthetic or natural colorants were discriminated as they were selectively adsorbed on cotton or RP-C18 sorbent columns, respectively. After elution, each fraction was monitored at 400, 530, and 610 nm for yellow, red, and green-blue-brown additives, respectively, with a DAD spectrophotometer. The screening method serves as a filter to indicate whether the target colorants are present above or below the detection limit of the method (6-15 or 25-10,000 n/mL for synthetic or natural colorants, respectively). Positive samples were discriminated by LC-DAD, using a flow system similar to that of the screening method. The LC-DAD discrimination/confirmation method is very sensitive; it exhibits a linear range of 0.01-50 microg/mL (excluding curcumin and caramel, which are linear up to 200 and 1,500 microg/mL, respectively). The method was applied to the determination of natural and synthetic colorants in dairy samples with good precision.
提出了一种简单新颖的食用色素筛选方法。合成色素或天然色素可分别通过选择性吸附在棉花或反相C18吸附柱上而得以区分。洗脱后，使用二极管阵列分光光度计分别在400、530和610nm波长下监测各馏分，以检测黄色、红色和绿-蓝-棕色添加剂。该筛选方法可作为一种过滤手段，用于指示目标色素的含量是高于还是低于该方法的检测限（合成色素为6-15或25-10,000 n/mL，天然色素分别为6-15或25-10,000 n/mL）。阳性样品通过液相色谱-二极管阵列检测法（LC-DAD）进行鉴别，其流动系统与筛选方法类似。LC-DAD鉴别/确证方法非常灵敏；其线性范围为0.01-50μg/mL（姜黄素和焦糖除外，它们的线性范围分别高达200和1500μg/mL）。该方法应用于乳制品中天然色素和合成色素的测定，精密度良好。
