Flow injection analysis. Part X. theory, techniques and trends

Abstract

The dispersion of sample zones in Flow Injection systems is described by analogy with the mixing of fluids in large-scale chemical reactors. This comparison has resulted in a definition of the sample zone dispersion, its mathematical description, and the identification of the main parameters which can be used to effect the desired degree of mixing. The miniaturized Flow Injection system, designed with the aid of the rules derived on the basis of the theory of dispersion, uses only 5-30 μl of sample solution and gives the analytical readout within 5-30 s after sample injection. The most recent Flow Injection methods, such as pH measurements at limited dispersion, voltammetry (including anodic stripping at trace levels), solvent extraction, and a new approach to enzymatic assays, are briefly reviewed to illustrate the trends towards future developments in continuous analysis in unsegmented streams. © 1978.