Comparación de métodos que utilizan ácido sulfúrico para la determinación de azúcares totales

This article presents a comparison between phenol-sulfuric acid method and two variations, that propose to vary the order of reagents addition or remove phenol reaction. It was performed several calibration curves to compare the slopes obtained from the straight-line equation. It was confirmed that the addition of phenol is not necessary for the quantification of total carbohydrates. The ability of the method to quantify different sugars (glucose, xylose, galactose and 1,3-β-glucan), the stability of the reaction, the agitation and the reaction volume were evaluated. A validation of calibration curve was made. It was concluded that the method for the determination of total sugars does not require the use of phenol and can reduce the final reaction volume of 8 mL to 1,3 mL. This research has a positive impact in order to reduce costs of reagents and the amount of wastes. Keywords: carbohydrates, sulfuric acid, phenol, spectrophotometry.