To detect fluorine ions conveniently without causing any problem of waste treatment by employing a mixture of ferrocene boric acid and an oxidation/reduction indicator.
When a mixture of ferrocene boric acid and an oxidation/ reduction indicator is added to a system where fluorine ions are present, a prominent variation takes place in the absorbance and thereby the fluorine ions can be determined qualitatively and quantitatively. The oxidation/reduction indicator includes methylene blue and Variamine blue effective from acidic region to neutral region and methylene blue is especially preferable because the variation of color tone is prominent. Mixture to be utilized as a reagent for detecting fluorine ion is prepared by mixing ferrocene boric acid, especially preferably, with 0.005-0.5 times in mol of oxidation/reduction indicator. Fluorine ions are normally measured in an aqueous solution with the eyes or using a visible ultraviolet absorptiometer.
ORI AIICHIRO
KURAUSU DOUSEMONDO
SHINKAI SEIJI
TOKUYAMA CORP
MITSUI PETROCHEMICAL IND