Heart-cutting two-dimensional liquid chromatography methods for quantification of 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole in Class III caramel colours

• Published in: Journal of Chromatography A Vol. 1198; pp. 73 - 79
• Main Authors: Moretton, Cédric, Crétier, Gérard, Nigay, Henri, Rocca, Jean-Louis
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 11.07.2008; Amsterdam; New York: Elsevier
• Subjects: 2-Acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole; Accuracy profile validation; caramel colors; Chromatography, Liquid - instrumentation; Chromatography, Liquid - methods; Class III caramel colours; food coloring; Food Coloring Agents - chemistry; food contamination; heart cutting two dimensional liquid chromatgraphy; Heart-cutting; imidazoles; Imidazoles - analysis; liquid chromatography; Reproducibility of Results; Two-dimensional liquid chromatography; Accuracy profile validation; Two-dimensional liquid chromatography; Class III caramel colours; Heart-cutting; 2-Acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2008.04.081

Heart-cutting two-dimensional liquid chromatography/UV detection methods were developed to determine 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole (noted as THI) in Class III caramel colours. In the first dimension, the caramel sample diluted in water was fractionated either by reversed-phase chromatography on C18 silica packing or by ion-exchange chromatography using strong cationic exchanger (SCX) stationary phase. In each case, THI elution domain was recovered in a loop and transferred to a second column packed with porous graphitic carbon (PGC) for the selective separation of THI. From the accuracy profiles with acceptance limit fixed at 20% and β-expectation tolerance interval fixed at 90%, the two methods, C18–PGC and SCX–PGC, were validated for THI/caramel ratios included between 5–50 and 10–50 ppm, respectively. Finally, the two methods were compared for the analysis of numerous caramel samples.