Fluoride Test (#90734)

Test disks and reagent for the semi-quantitative determination of fluoride ions. Gradation 0 - 2 - 5 - 10 - 20 - 50 - 100 mg/l F (each kit contains a color comparison scale). The reaction is based on the bleaching action of fluoride ions on an aluminum color complex. The fluoride test is especially suited for rapid control of fluoride concentrations. Its purpose is to define concentration ranges and to detect values which fall short of or exceed given limits. Chlorates and bromates cause white discolorations of the test paper. Addition of sodium dithionite will circumvent this interference without affecting the fluoride test. Large concentrations of sulphate also cause discolorations. Addition of barium chloride (BaCl 2 ) eliminates this interference. When testing intensely coloured solutions the color of the sample must be taken into account for evaluation.