Speciation applications of the flow-injection technique are discussed in relation to the hydrodynamic manifold components that are adapted for this purpose. Alterations include double halting of the propulsion system, coupling of injection valves, modifications of the transport-reaction zone, use of switching valves, and merging and splitting points. Detector remodelling, the use of sensors and special detectors, and data processing methodologies are also reviewed in connection with the flow-injection/chromatography coupling. Finally, foreseeable trends and desirable advances are outlined.