Perfetti G A, Joe F L, Fazio T, Page S W
Food and Drug Administration, Division of Food Chemistry and Technology, Washington, DC 20204.
J Assoc Off Anal Chem. 1988 May-Jun;71(3):469-73.
Liquid chromatographic (LC) methodology potentially useful for the characterization of orange juice, with particular regard to detecting adulteration of orange juice by computer pattern recognition analysis, has been developed. After dilution with methanol the juice is extracted with hexane to remove the carotenoids, which are chromatographed on a C18 column with an acetonitrile-methanol-methylene chloride mobile phase and detection at 450 nm. Further extraction of the juice with methylene chloride isolates the methoxylated flavones, which are chromatographed by reverse phase LC with an acetonitrile-methanol-water mobile phase and detection at 280 nm. The flavanone glycosides remaining in solution are chromatographed on a C18 column with an acetonitrile-water mobile phase and detection at 280 nm. The precisions of the heights of the 32 LC peaks selected for pattern recognition analysis were determined from 5 replicate analyses of a single juice. Coefficients of variation of the replicates ranged from 0.3 to 4.5%, with an average of 2.1%. Adulteration of products with sodium benzoate-fortified pulpwash or grapefruit juice can be detected by this method. Pattern recognition analysis of the data obtained for 80 authentic and 19 adulterated orange juices showed that the method is potentially useful for distinguishing between authentic and adulterated products.
已开发出一种液相色谱（LC）方法，该方法可能有助于橙汁的表征，特别是通过计算机模式识别分析来检测橙汁的掺假情况。用甲醇稀释后，用己烷萃取果汁以去除类胡萝卜素，然后在C18柱上用乙腈 - 甲醇 - 二氯甲烷流动相进行色谱分析，并在450nm处检测。用二氯甲烷进一步萃取果汁可分离出甲氧基黄酮，通过反相液相色谱用乙腈 - 甲醇 - 水流动相进行色谱分析，并在280nm处检测。溶液中剩余的黄烷酮糖苷在C18柱上用乙腈 - 水流动相进行色谱分析，并在280nm处检测。从单一果汁的5次重复分析中确定了为模式识别分析选择的32个液相色谱峰高度的精密度。重复分析的变异系数范围为0.3%至4.5%，平均为2.1%。该方法可检测出用苯甲酸钠强化果肉洗液或葡萄柚汁掺假的产品。对80份正宗橙汁和19份掺假橙汁获得的数据进行模式识别分析表明，该方法可能有助于区分正宗产品和掺假产品。
