High performance separation methods in phytoanalytical chemistry: new approaches and perspectives

High Performance Separation Methods in Phytoanalytical Chemistry: New Approaches and Perspectives Danilo Corradini National Research Council, Institute of Chemical Methodologies, Area della Ricerca di Roma 1, Via Salaria Km 29.300, 00016 Monterotondo Stazione (Rome), Italy. danilo.corradini@cnr.it Plants are a source of fine chemicals, most of which are considered to be responsible for nutritional, sensory properties and beneficial influence on human health of agri-food and have provided inspiration for the active ingredients in medicines. Most of these compounds are secondary metabolites produced within the plants besides the primary biosynthetic and metabolic routes. Rapid separation, identification and quantification of phytochemicals, the active components for biological activity of plant tissues, play a key role in phytochemical investigations of edible plants and crude plant extracts and a wide spectrum of analytical methods have been developed for application in phytochemical research. Most of these methods are based on chromatographic and electromigration separation techniques. This communication discusses a variety of factors that influence both electrophoretic and chromatographic behavior phytochemicals with the purpose of developing novel analytical separation methods for the identification and quantification of phytochemicals in plant extracts and foodstuff. The presentation evaluates the influence of the composition of either the electrolyte solution (BGE) or the mobile phase on the selective separation of representative compounds of plant interest in capillary zone electrophoresis (CZE) and RP-HPLC, respectively. Appropriate selection of either the BGE in CZE or the mobile phase in RP-HPLC involves the evaluation of the equilibrium in solution that might take place between the analytes and the components of such solutions. Also compared is the complementary separation power of RP-HPLC and CZE for given classes of phytochemicals. It is evidenced that the appropriate selection of the composition of either the BGE or the mobile phase involves the evaluation of the physical-chemical properties of the liquid phase and the equilibrium in solution that might take place between the analytes and the components of such solutions. The result is the well-known possibility of tailoring selectivity and efficiency of the considered separation systems by incorporating suitable organic solvents, buffering agents, and additives into the BGE or the mobile phase, respectively. Practical applications of these studies to the development of analytical methods for the separation of biomolecules in complex matrices of plant origin are reported and pros and cons aspects of HPLC and CZE for the selected analytical separation problems are discussed too.