Theory of Dispersion Related to FIA

The flow injection analysis (FIA) response curve is a result of two processes, both kinetic in nature the physical process of dispersion of the sample zone within the carrier stream and the chemical process of formation of a chemical species. These two processes occur simultaneously, and they yield, together with the dynamic characteristics of the detector, the FIA response curve. Simultaneous dispersion and chemical reaction have been studied in flow systems as used in chemical reaction engineering and in chromatography, and, therefore, the theories of these two areas are related to the theory of FIA. This is why most papers about FIA theory have adopted, as a starting point, the classical theory of flow in tubular conduits, with the intention of developing mathematical expressions for peak broadening, mean residence time, and fractional conversion of the analyte to a detectable product. 

The physical process of material dispersion is due to the hydrodynamic processes taking place in the flowthrough system and is therefore conveniently investigated by the stimulus response technique, which is based on introduction of a tracer into a flowing stream and on measurement of the dispersion of the tracer as caused by the transport process throughout the system. If the tracer is injected as a zone (stimulus), then the observed 

It might appear that the FIA flow channel has the same function as a postcolumn reactor, and therefore the flow injection systems could also be optimized solely by means of the predictive models developed for chromatography, simplified for zero retention, or by means of input-re- 

The wealth of literature, dealing with dispersion phenomena in straight and coiled tubes and packed and mixed reactors [20, 72, 73, 74, 75, 142, 146, 150, 151, 153, 176, 181, 183, 343, 345, 430, 501, 566, 608, 665, 702, 802, 1061, 1063, 1064, 1065, 1226, 1248, 1256, 1273] describes concepts and models, which are useful for gaining insight into what happens during 

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