Fluorometric determination of inulin using 5-quinolineboronic acid and inulinase.

Inulin is a polysaccharide composed mainly of D-fructose units and is the most reliable indicator of the glomerular filtration rate. We have proposed an inulin detection method that involves the hydrolysis of inulin to D-fructose using inulinase and the selective binding of D-fructose from inulin using 5-quinolineboronic acid. In this method, the fluorescence of 5-quinolineboronic acid increases, depending on inulin concentration. For inulin in plasma, the detection and quantitation limits were calculated to be 3.7 and 11 μg/ml, respectively.