Continuous Monitoring of Industrial Processes by FIA

For process control applications, FIA offers the benefit of real-time continuous monitoring by regularly aspirating sample solution (e.g., from a batch-type chemical reactor) into a carrier-wash solution, the detector of choice being operated in an impulse response mode. Thus a chemically modulated signal, continuously recorded as a series of peaks (injected material on a constant background of carrier-wash), offers a positive 

There are three approaches for process control applications utilizing peak height (or vertical readout) as the source of information. They are based on sample injection, standard injection, and reagent injection. 

Sample injection (Fig. 8.2) follows the scheme most frequently used in the laboratory applications of FIA a solution (S) from a reactor, or a 

The standard injection manifold (Fig. 8.3) does not require an injection valve and is therefore mechanically less complex. The analyte ( S) is con- 

Reagent injection (Fig. 8.4), first designed to monitor the content of nutrients in seawater [279, 822], saves reagents by injecting small volume of these (by means of pump FI) only at the times when a readout is required, while the analyte solution (5) is pumped continuously through the FIA channel. The carrier stream (C) is used to dilute and/or precondition the sample solution, detector (D) monitoring the composition of the flowing stream. Since detectable species is formed only in the presence 

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