ISO/TS 17951-1:2016 specifies a method for the determination of fluoride in waters, waste waters and effluents by flow injection analysis (FIA). Any insoluble or complexed fluoride is converted to fluoride ion by a manual distillation procedure from sulfuric/phosphoric acid. Fluoride ion in the distillate is measured using flow analysis with lanthanum alizarin complexone and spectrometric detection. This method is applicable to industrial waste waters, effluents, surface waters, ground waters, leachates. It is not recommended for drinking waters where a distillation step is not required. In ISO/TS 17951-1:2016, two working ranges are described:
- working range I: 0,1 mg/l to 1 mg/l;
- working range II: 1 mg/l to 10 mg/l.
The specification of the calibration solutions are to be adapted accordingly.