Determining fluoride ions in ammonium desulfurization slurry using an ion selective electrode method

Determining fluoride ions in ammonia desulphurization slurry using a fluoride ion selective electrode (ISE) is investigated. The influence of pH was studied and the appropriate total ionic strength adjustment buffer and its dosage were optimized. The impact of Fe³⁺ concentration on the detection results was analyzed under preferable conditions, and the error analysis of the ISE method's accuracy and precision for measuring fluoride ion concentration in the range of 0.5-2000 mg/L was conducted. The quantitative recovery of F⁻ in ammonium sulfate slurry was assessed. The results showed that when pH ranged from 5.5∼6 and the Fe³⁺ concentration was less than 750 mg/L, the accuracy and precision test results with quantitative recovery rates of 92.0%-104.2% were obtained.