Chapter VII Continuous Separation Techniques in Flow-Injection Analysis

Publisher Summary Chromatographic and non-chromatographic continuous separation processes are currently among the most relevant aspects of analytical chemistry. Both are characterized by the continuous motion of one or both liquid or gas phases involved, accomplished by means of a propelling system—for example, a peristaltic or piston pump, and pressurized gas. The liquid (gas) sample can be introduced into the system either by injection or insertion, or by continuous aspiration. These systems generally accommodate a continuous detector allowing identification and/or quantitation of the analytes concerned. One of their most interesting features is the possibility to decrease to a greater or lesser extent human participation in the analytical process (automatization). This trend toward automatization has been reinforced with the increasing use of the currently irreplaceable microprocessors, used both to control the process and for data acquisition and treatment purposes. There are three analytical hydrodynamic techniques of widespread use—namely, high performance liquid chromatography (HPLC), field flow fractionation (FFF), and continuous flow analysis (CFA) in its two chief variants: segmented flow analysis and flow injection analysis (FIA).