Online fluoride ion analyzerTesting method:

Ion chromatography method

Fluoride ion selective electrode method

Fluorine reagent spectrophotometric method

Range: 1-100ppm (expandable range)

Online fluoride ion analyzerElectrode selection method:

Fluoride ion selective electrode is a type of sensor that uses lanthanum fluoride (LaF3) single crystal as the sensitive membrane, and is a typical crystal electrode. Due to the strict limitation of single crystal structure on the ions that can enter lattice exchange, it has good selectivity. The structure of this electrode is shown in Figure 3-30. When measuring, it forms the following primary cell with the reference electrode and the measured solution:

F - Select electrode.

Fluorine reagent spectrophotometric method.

Fluorine reagent, also known as Alizarin chelating agent (ALC), with the chemical name 1,2-dihydroxyanthraquinone-3-methylamine-N, N-diacetic acid. In a pH 4.1 acetate buffer medium, it reacts with fluoride ions and lanthanum nitrate to form a blue ternary complex. The color depth is proportional to the fluoride ion concentration and can be quantified by colorimetry at a wavelength of 620nm.

Ion chromatography method.

See the determination of nitrogen-containing compounds.