A method for the determination of fluoride in coal using pyrohydrolysis for sample decomposition is proposed. An apparatus was constructed, and the influence of vanadium pentoxide (V2O5) as a catalyst for the pyrohydrolysis reaction was investigated. It was verified that V2O5 does not influence the release of fluoride from coal. Certified and non-certified samples were analysed using an ion selective electrode (ISE) for analyte detection. Precise (RSD < 7%) and accurate (recovery in accordance with certified values) results were obtained. The limit of quantification (LOQ) of the method was 5.0 mgF/g of sample, using 20 mg of sample and a final dilution to 10 mL. The sample frequency was 5 samples h-1.
coal; fluoride; pyrohydrolysis; ion electrode; vanadium pentoxide; catalyst
