A catalytic-kinetic method for the determination of traces of fluoride in biological material

A catalytic-kinetic method for the determination of nanogram amounts of fluoride, based on its inhibiting action on the catalyst in the zirconium-catalyzed reaction between perborate and iodide, is described. The rate measurements are accomplished very simply by using a Landolt reaction system with a biamperometric detection of the induction period. The standard deviation in the working range 19–190 ng of fluoride (1–10 nmol) is ± 2 ng. The method can be made specific by combining it with a separation of the fluoride by microdiffusion. This has been demonstrated by analyzing biological material and comparing the results with the fluoride contents obtained with other methods.