González Mónica, Gallego Mercedes, Valcárcel Miguel
Department of Analytical Chemistry, Campus de Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
J Agric Food Chem. 2003 Apr 9;51(8):2121-9. doi: 10.1021/jf0261147.
Five synthetic and five natural colorants were determined in lyophilized dairy products and fatty foods using an automatic method based on lixiviation and a solid-phase extraction process that includes cotton and RP-C(18) columns for the sequential retention of synthetic colorants and natural colorants, respectively. The lyophilization of the sample coupled with the separation procedure provides clean extracts despite the complexity of the matrices studied. In addition, the lyophilization process preserves the sample for at least 2 months without changes in the concentrations of the colorants. Identification and determination of synthetic and natural colorants were carried out using a liquid chromatograph equipped with a diode array detector. The detection limits achieved for all of the colorants (0.03-75 microg/g of lyophilized sample) allowed their determination within the limits established by the European Union, with good precision (approximately 4.5%). In addition, colorants spiked to different foods provided average recoveries (spiked at three concentration levels in four types of dairy samples and in three types of fatty foods) near 94 +/- 4%.
采用一种基于浸提和固相萃取过程的自动方法，分别使用棉花柱和反相C(18)柱依次保留合成色素和天然色素，测定了冻干乳制品和脂肪类食品中的五种合成色素和五种天然色素。尽管所研究的基质复杂，但样品的冻干结合分离程序可提供纯净的提取物。此外，冻干过程可使样品保存至少2个月，色素浓度无变化。使用配备二极管阵列检测器的液相色谱仪对合成色素和天然色素进行鉴定和测定。所有色素的检测限（0.03 - 75微克/克冻干样品）使其能够在欧盟规定的限值内进行测定，精密度良好（约4.5%）。此外，添加到不同食品中的色素（在四种类型的乳制品样品和三种类型的脂肪类食品中以三个浓度水平添加）平均回收率接近94±4%。
