Fluidized particles in flow analysis: potentialities, limitations and applications

In flow analysis, solid particles (sorbents, reagents or catalysts) have been used for e.g. analyte separation/concentration, sample clean-up, speciation analysis, enzymatic assays, analysis relying on slight soluble reagents, and kinetics studies related to adsorption/release of species. The particles are usually accommodated inside packed-bed mini-columns, cartridges or disks, but this geometry may led to limited analyte/particle interaction, poor renewal of the particle surface, swelling effects, establishment of preferential pathways, and increased backpressure. These hindrances are circumvented by fluidizing the solid particles. Fluidization is a worldwide-accepted industrial process, which can be successfully implemented in flow analysis. This review emphasizes historical and conceptual aspects, as well as advantages, limitations, applications, and perspectives for future development of flow analysis relying on fluidized particles.