Abstract
Examinations were made on the determination of organic fluorine compounds in which the fluorine compound is burned in a quartz combustion tube in oxygen stream and the fluoride formed is absorbed by a reagent filled in a quartz absorption funnel with cap. Experiments were made with NaF, MgO, ZrO2, CeO2, MnO2, PbO2, and Fe2O3 as the fluoride-absorbing agent and Fe2O3 showed the best absorptivity. When an organic fluorine compound is burnt, fluorine changes into hydrogen fluoride and reacts with quartz to form silicon tetrafluoride, but a part of it is still in equilibrium with hydrogen fluoride and reacts as shown by equation (1). In the present series of experiments, the determination was carried out with an apparatus shown in Fig. 1, the sample was burnt, the fluoride formed was absorbed by an absorption funnel filled with granular Fe2O3, and the amount of fluorine was calculated from the increase in weight of the funnel. Analytical values so obtained tended, to be smaller and this was attributed to the trace of boron contained in the combustion tube which had reacted with fluorine to form boron trifluoride.
