Comunicación corta CARACTERÍSTICAS METROLÓGICAS EN LA DETERMINACIÓN DE ÁCIDOS URÓNICOS PARA EL CONTROL DE LA CALIDAD EN MEZCLAS DE OLIGOGALACTURÓNIDOS Short communication Metrological characteristics in uronic acid determination for quality control of oligogalacturonide mixtures

Uronic acid content determination for the quality control of oligogalacturonides is extremely important, considering that they are directly related to their biological activity. The aim of this research was to analyze the metrological characteristics of Blumenkrantz and Asboe-Hansen spectrophotometric method, for uronic acid determination in oligogalacturonide mixtures, by using m-hydroxydiphenyl as chromophore. Linearity, precision and limits of detection and quantification were among the metrological characteristics analyzed. Blumenkrantz and Asboe-Hansen method resulted to be adjusted to a linear model within a concentration range of 10-80 μg mL -1 . Regarding such model, the correlation coefficient value is r= 0,996 whereas the determination coefficient is R 2 = 0,992, indicating a very good correlation between uronic acid concentration and its absorbance. The precision of this method was determined through two procedures, which did not surpass the established value as a variability limit of 5 %. Detection and quantitation limits were in the order of 1,6 ± 0,4 μg mL -1 and 5 ± 1 μg mL -1 , respectively. Uronic acid concentration was recorded in the order of 890 μg mL -1 .