Abstract

Column switching (CS), which first appeared as a method for the direct insertion of unprocessed biological samples, is now the more adaptable method for the completely automated integration of sample preparation and chromatographic analysis. The complexity of the matrix is addressed at the smallest scale by CS, which also permits the injection of sample volumes that are bigger than those supported by capillary/nano analytical columns. While maintaining the analytical capillary/nano column and the instrument’s correct operation, detectability can be considerably increased. Fully downsized CS systems have been continuously developed during the past twenty years. Innovative polymeric, inorganic, and nanomaterials-based extraction phases have been developed and used in a variety of column forms, including extraction media that are packed with particles, monoliths, fibres, and open tubes. This essay examines the most recent developments in Technology for totally downsized column-switching systems using micro extraction columns. We will review the potentialities, benefits, and limitations of contemporary sorptive phases and extraction. The overview will highlight how important those advancements are for bioanalytical applications.