Continuous filtration as a separation technique

Filtration was an old-fashioned technique that has gained widespread significance in the analytical process by its implementation in continuous systems, mainly flow-injection manifolds. Two different approaches can be employed in coupling filtration to continuous systems in order to separate a heterogeneous solid–liquid medium. We review both approaches, whether with a filter or filterless, including their applications in current examples that demonstrate their usefulness. Filterless devices can use auxiliary energies, most commonly ultrasound, or centrifugal force in the stream carrying precipitate. The interest of analysts in continuous filtration as a versatile, easy-to-automate separation technique has increased at the expense of centrifugation, which is more difficult to automate.