Carryover is an integral part of all continuous flow methods and is a result of longitudinal dispersion that occurs as liquids travel down tubes. Segmentation minimizes the dispersion resulting in the near rectangular output of a SFA signal. FIA methods, on the other hand, rely on the carrier solution to wash remnants of the sample out of the tubing. The Gaussian shape of FIA peaks is indicative of the dispersion within the tube. In fact, it is carryover that limits the applicability of FIA methods to reactions that develop color quickly so that the internal volume (flow path) is kept small. Larger flow paths result in FIA peaks with carryover so extreme that sample segments blend with each other. It is in these cases that segmentation is required.
