Nigay SA, ZI de la Gare, La Féculerie, Feurs, France.
J Agric Food Chem. 2011 Apr 27;59(8):3544-50. doi: 10.1021/jf104464f. Epub 2011 Mar 17.
4-Methylimidazole (4MeI) is a nitrogen compound formed during the manufacture of class III and IV caramel colors. The European Commission has limited its content to 250 ppm. Two methods were compared to perform 4MeI quantification in caramels. The first one, currently used and considered to be the reference method, consists of a hot extraction of caramel color with dichloromethane and an analysis of the acetyl derivative of the extract by gas chromatography coupled to mass spectrometry (GC-MS). The second method is based on the heart-cutting two-dimensional liquid chromatography technique (LC-LC) to directly separate 4MeI from the other components present in caramel color sample (diluted in water) in <30 min. The accuracy profile validation method and the comparison between the results obtained with the two methods show that the new and completely automated LC-LC method is usable to quantify 4MeI in caramels.
4-甲基咪唑（4MeI）是在 III 类和 IV 类焦糖色素制造过程中形成的含氮化合物。欧盟委员会已将其含量限制在 250ppm 以内。本文比较了两种方法来对焦糖色素中的 4MeI 进行定量分析。第一种方法目前正在使用，被认为是参考方法，包括用二氯甲烷对焦糖色素进行热萃取，以及通过气相色谱-质谱联用（GC-MS）对萃取物的乙酰衍生物进行分析。第二种方法基于二维液相色谱（LC-LC）的切心法，可在 <30 分钟内直接将 4MeI 从焦糖色素样品（用水稀释）中的其他成分中分离出来。准确度验证方法和两种方法的结果比较表明，新的完全自动化的 LC-LC 方法可用于定量测定焦糖中的 4MeI。
