Segmental flow injection with ion-selective electrodes for the determination of fluoride in water

A flow analyser with enhanced sampling frequency combining the features of flow-injection and continuous-flow analysis is described. Parameters of the analyser were optimized to ensure the highest rate of analysis allowed by the bubble-through flow cell with fluoride-selective electrodes. Fluoride was determined in 0.1-ml water samples with a sampling rate as high as 720 h −1 and a relative standard deviation better than 1%.