| abstract |
The invention relates to a method of determining fluoride using functionalised silicon oxides. The inventive method consists in preparing silicon oxides that are functionalised with organic molecules which can emit a macroscopically-measurable signal when they dissolve, through the activation of the surface of the inorganic material, the anchoring of the active molecule and the elimination of non-anchored reagents. Once the functionalised solid has been obtained, the method of determining fluoride comprises the following steps: 1a) suspension of the solid in an acid buffer solution; 2a) distribution of aliquots from the suspension and digestion; 3a) optionally, filtration and spectroscopic measuring on the solution. The materials used comprise the following compositions: (SiO2)1-x-y[SiO(4-n)/2(OH)n]x(SiO3/2R) and (SiO2)1-x-y-z(AoOa)z/o(M2O)z'[SiO(4-n)/2(OH)n]x(SiO3/2R)and 0 ≤ x ≤ 1; 0 < y < 1; 0 ≤ z ≤ 1; 0 < z' < 0.5; n = 1, 2; A: metal from groups (3-7)A and (1-8)B, M: alkali metal; R: organic molecule (microscopic signal in solution). Said materials can be obtained in the form of dispersed powders or monoliths. |