What is injection segmented flow analysis (iSFA)?
An OI Analytical innovation, iSFA provides the high precision of sample injection with the long reaction times, turbulent mixing conditions, and limited dispersion characteristics of SFA. An excellent example where iSFA provides distinct analytical and convenience advantages is the determination of nitrate by cadmium reduction. Due to diffusion-limited mixing in FIA, a packed column must be used to provide the high surface area of reaction sites necessary to perform efficient and complete reduction. In contrast, air bubble segmentation significantly increases the reduction rate of nitrate to nitrite in a cadmium coil by generating bolus flow to enhance liquid–coil wall interactions. The cadmium coil is preferable to a packed column since it does not require manual repacking or handling and disposal of hazardous cadmium by the operator. Additionally, it is insensitive to air, while a packed column must be repacked if air accidentally becomes entrapped in the column. Finally, the coil ca
