Capillary zone electrophoresis analysis of additives in food samples

Abstract

Which analytical technique is used very often is determined by the physical properties of the compounds to be analyzed. Highly volatiles and slightly polar compounds can be examined by gas chromatography (GC) and nonvolatile and polar compounds by high performance liquid chromatography (HPLC) or thin layer chromatography (TLC). The highly polar or low volatility compounds quite often require special conditions in HPLC, mobile phases (e.g. ion pairing) or stationary phases (ion exchange) which are troublesome to handle and result in poor reliability, efficiency and separation capability. Figure 39.1 shows compounds arranged according to polarity and volatility. The domain of GC is located on the left hand side, HPLC ideally fits into the middle and partially onto the right hand side depending on analytical modes or stationary phases, while capillary zone electrophoresis (CZE) is best suited to analysis of the non-volatile, hydrophilic analytes. From these facts the analysis of artificial sweeteners and synthetic dyes has been selected to demonstrate the capabilities of CZE.