Colorimetric Determination of Tertiary Hydroxyl Group in the Membrane Material (SXFA) of SAW Chemosensor

The trialkyliodide was formed by the reaction of tertiary hydroxyl group in SXFA with HI. In H2SO4 solution (1+9) of pH 4,I2 was generated quantitatively by the reaction of trialkyliodide with KIO3,and the I2 was dissolved in cyclohexane,having its absorption maximum at 525nm. Based on these factors,the determination of tertiary hydroxyl group in SXFA by colorimetry was proposed. Tert-butyl alcohol was used as standard sample for preparation of standard curve,taking the mass of hydroxyl group as the ordinate and values of absorbance as the abscissa. The content of hydroxyl group in SXFA was found from the standard curve with the values of the absorbance measured. The sample was burned in oxygen bomb,HF gas obtained was absorbed with water,and the content of F in SXFA was determined by ion chromatograph. It was found that the molar ratio of F to hydroxyl group obtained was checked quite well with that in the structural formula.