From extracts to quantitative analyses: Method validation, analytical approaches (chromatographic, spectroscopic, and electrochemical procedures) and innovative instrumentations LC × LC

Phytochemicals comprise a wide variety of bioactive compounds naturally found in plants characterized by their health-promoting effects. These have been widely investigated and used since early human history for the treatment of numerous diseases. Nowadays, major concerns lie in the efficacy, safety, and quality of phytotherapeutics. Therefore, it is crucial to develop reliable and reproducible methods that guarantee accurate and precise results in the identification and quantification of phytochemicals under a quality assurance/quality control. In this context, liquid chromatography coupled to mass spectrometry has gained popularity due to its improved separation and detection. This chapter provides an overview on the determination of phytochemicals, from characterization and quantification, with special emphasis on method validation and the analytical quality parameters. The main techniques used for their analysis (mainly chromatographic, spectroscopic, electrochemical procedures) are described. Also, comprehensive two-dimensional liquid chromatography is proposed as an attractive method for their quali-quantitative determination.