Indirect determination of fluoride in aqueous samples by inductively coupled plasma atomic emission spectrometry following precipitation of CeF3

An indirect fluoride determination method has been developed based on the ICP-AES determination of excess cerium(III) ion after precipitation. From four cations—Y(III), Sr(II), Ce(III), La(III)–cerium(III) proved to be the best precipitate forming cation in the 0–20 mg L−1 fluoride concentration range with the limit of detection of 1.4 mg L−1. The precision (RSD) of the proposed method is 0.71% at 8 mg L−1 fluoride. The role of sulphate ions in the formation of the fluoride precipitate was studied as well. The applicability of the technique for the study of solid hazardous wastes as well as for groundwater monitoring of a fluoride contaminated area is demonstrated.