The Determination of Methylxanthines in Chocolate and Cocoa by Different Separation Techniques: HPLC, Instrumental TLC, and MECC
Abel Carlin-Sinclair and Iman Marc
Département de Chimie, Université de Versailles-Saint-Quentin-en-Yvelines, Bâtiment Descartes, 78035 Versailles, France
Laurence Menguy and Damien Prim
Université de Versailles-Saint-Quentin-en-Yvelines, Institut Lavoisier–UMR CNRS 8180, Bâtiment Lavoisier, 78035 Versailles, France
The comparative determination of three methylxanthines (caffeine, theobromine, and theophylline) in chocolate and cocoa extracts is obtained in four successive laboratory experiments. The first step is the separation of targeted molecules from complex natural matrix through the solid-phase extraction technique and the preparation of standards required for high-performance liquid chromatography (HPLC), micellar electrokinetic chromatography (MECC), and instrumental thin-layer chromatography (I-TLC) analyses. Next steps are the optimization of the separation process of the three methylxanthines and analysis of aliquot extracts in HPLC, MECC, and I-TLC. Comparison of results from each sample and technique as well as advantages and drawbacks of each technique are discussed.
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