Spectrophotometric Determination of Sugar Alcohols Utilizing a Reaction with Titanium Alkoxides

It was found that the UV-absorbance of sugar alcohols was enhanced by a reaction with titanium alkoxide {titanium tetraisopropoxide (TTIP)}. 29- and 146-fold increases of the absorbance of sorbitol and xylitol at 250 nm by reactions with TTIP were found, respectively. Good linear relationships (r≥0.9794, n = 5) between the absorbance at 250 nm and the concentration of these sugar alcohols were obtained. When a 4.9 mM sorbitol aqueous solution was used as the sample, the repeatability, including the sample-preparation step, became 6.0% (n = 3) as the relative standard deviation.