What is segmented flow analysis (SFA)?
Like flow injection analysis (FIA), SFA is a continuous flow technique; however, SFA differs in several important ways. First, the sample is aspirated rather than injected into the system. As it combines with the first reagent, the stream is segmented by a regular pattern of air bubbles. This causes the flowing stream to become distributed into mixing packets. Bolus flow causes the alternating segments of air and liquid to rotate against each other, generating turbulent flow for highly efficient mixing. SFA typically requires that the inner walls of the tubing become coated or conditioned with a surfactant. The surfactanc promotes smoother and more reproducible flow in segmented streams. However, this requirement lengthens the system startup and shutdown times slightly, so SFA is not as rapid as FIA for method changeovers.
