Applications of Two-Dimensional Liquid Chromatography to Natural Product and Food Analysis

Food and natural products are complex materials that contain many different types of compounds relevant to human health. Characterization of these materials using any single analytical method is difficult due to both the large range in physico-chemical properties (e.g., lipids and carbohydrates in the same sample), and the number of structurally similar molecules that can be present (e.g., isomers of oligomeric polyphenols). Two-dimensional liquid chromatography (2D-LC) is a powerful approach to address these challenges using both targeted and untargeted analyses. In this chapter we summarize and discuss recent trends in the use of 2D-LC for characterization of major (carbohydrates, proteins, etc.) and minor (e.g., polyphenols, saponins, etc.) in a variety of materials ranging from wine to wheat flour. Recent developments in instrumentation and methodology have enabled new approaches that target specific challenges related to particular sample types (e.g., analysis of water- and fat-soluble vitamins in a single analysis). Further progress in this area will benefit from more streamlined approaches to method development.