Peak Height, Channel Length, and Flow Rate

3 Peak Height, Channel Length, and Flow Rate 

The microreactor between the injection port and the detector may have different length, diameter, and geometry. 

Rule 2. Limited dispersion value D is obtained by injecting a sample volume of minimum one Smz into a manifold consisting of the shortest possible piece of a narrow tube connecting the injection port and the detector. 

Even if a medium dispersion FIA system is required, it is economical to use narrow channels. The sample and reagent economy is improved when narrow channels are used, because, for the same linear flow velocity, the pumping rate Q in a tube of diameter d is only one-fourth of that required for a tube of diameter Id. On the other hand, practical considerations prevent the use of channels with too narrow a bore or too tightly packed reactors because  

The flow resistance will increase, thus preventing the use of a low-pressure drive (peristaltic pump, air drive, piston burette). 

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