флуор

In this study, physically and chemically modified chitosan; protonated glycerol diglycidyl ether cross-linked chitosan beads (GDCLCB/H⁺) were prepared and characterized using FTIR and SEM. The optimum defluoridation capacity (DC) of GDCLCB/H⁺ was observed at the initial F- ion concentration of 15 mg/l, adsorbent dosage of 0.6 g, contact time of 30 min and pH of the solution was in the range of 5–7 at 303 ± 2 K. The equilibrium adsorption data fitted well with Langmuir and Freundlich isotherm models.

A technique for direct spectrophotometric determination of total fluorine in products for oral hygiene using a mixed ligand complex La(III) and alizarin-complexone with fluoride ion in the presence of a non-ionic surfactant has been developed. A number of complexes of different stoichiometry formed in the system has been found. The La:alizarin-complexone:F^- = 1:2:1 complex was shown to be used as an analytical form. The complex in the presence of Tween 80 is characterized by the molar absorptivity ε₆₂₀ = 11000 mol∙dm^-3∙cm^-1.