3.1. Sequential Injection

Sequential Injection, based on stacking a sequence of sample and reagent zones into a holding coil uses flow programming to meter solutions, to mix the stack, and transport it into flow cell. SI benefits from advantages of flow programming, but it has the same limitations as single stream FI, due to limits of axial mixing. Sequential Injection, a forerunner to programmable FI, is discussed in this chapter with aim to compare performance of SI and pFI methods in microflow, lab-on-valve based format.