Application of three-dimensional liquid chromatography for quantification of 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole (THI) in caramel colours

• Published in: Analytical methods Vol. 8; no. 35; pp. 6573 - 6579
• Main Authors: Moretton, Cédric, Nigay, Henri
• Format: Journal Article
• Language: English
• Published: 01.01.2016
• Subjects: Byproducts; Caramel; Carbon; Color; Colour; Liquid chromatography; Mathematical analysis; Regulations
• ISSN: 1759-9660; 1759-9679
• DOI: 10.1039/c6ay00686h

Multidimensional chromatography is a widely used technique to quantify specific compounds in complex samples. A three-dimensional liquid chromatography with UV detection was developed to separate 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole, an undesirable neoformed by-product found in class III caramel colours. The first column was a classical reversed-phase column (C18 column); the second one was a cation-exchange column operated with acidic mobile phase; the last column was a specific reversed-phase column (porous graphitic carbon). This method is validated to quantify this compound in caramel colours in 45 min in the 5-50 mg kg −1 concentration range. The limit of quantification is found at 5 mg kg −1 . The total error is less than 20% at 5 mg kg −1 and less than 10% between 10 and 50 mg kg −1 . This method is used routinely to quantify THI in class III caramel colours and to check compliance with caramel regulations. This study described a new method to quantify THI in caramels colours without sample preparation thanks to the separation power of multidimensional liquid chromatography.