Basic Principles of Chromatography

Chromatography has many applications for analysis of various foods components. It differs from other methods of separation in that a wide variety of materials, equipment, and techniques can be used. This chapter focuses on the principles of chromatography, while background information for the detailed principles and application of high-performance liquid chromatography (HPLC) and gas chromatography (GC) is covered in Chaps. 13 and 14 , respectively. This chapter gives the basics of chromatography as a separation method based on the partitioning or distribution of a solute between a mobile phase and a stationary phase. Based on the physicochemical characteristics of the analyte and the availability of instrumentation, a chromatographic system is chosen to separate, identify, and quantify the analyte. Chromatographic separation modes include normal-phase, reversed-phase, hydrophilic interaction, hydrophobic interaction, ion exchange, affinity, and size exclusion chromatography. Factors to be considered when developing a separation include mobile phase variables, as well as column efficiency, selectivity, and capacity. Following detection, a chromatogram provides both qualitative and quantitative information via retention time, peak area data, and/or spectral analysis.