Theoretical considerations of Flow Injection Analysis in the Absence of Chemical Reactions

The fundamental mechanism of flow injection analysis (FIA) is assumed to be simple dissusion and the response of the detector is included in a model description that provide information about the shape of the FIA peak in terms of, basically, five parameters. Two of the five parameters are associated with the compound while the rest yield information about the solvent and friction. By introducing a kinetic-diffusion coefficient, it is shown that the shape of the FIA peak is well described by the theory for diffusion of K3(Fe(CN)6), K2CrO4 and Ni(NO3)2 in distilled water. It is suggested that any deviation from the features of the present model and the results of a tentative chemical reaction with one of the test compounds, is related to chemical kinetics.