Chemometric Approach to Quantify 5-Hydroxymethylfurfural and Furfural Obtained from Sugarcane Bagasse and Peanut Hull by UV

Abstract

5-hydroxymethylfurfural (HMF) is considered a platform chemical used for producing industrial purpose carbon-based compounds. During HMF synthesis, the compound furfural (FF) is formed as a byproduct. Using spectrophotometric UV is not feasible because HMF and FF overlap around 280 nm, demanding separation techniques as high-performance liquid chromatography (HPLC). This work aimed at applying a synthetic route for HMF production by using wastes such as sugarcane bagasse and peanut hull, and developing a quantification method of HMF and FF compounds using UV spectra and pseudo-univariate calibration based on multivariate curve resolution with alternating least squares. HMF synthesis was studied using inorganic acids in a closed reflux system followed by a biphasic extraction with n-butanol as an organic solvent. When comparing their respective biomass, sugarcane bagasse provides a higher amount of HMF, reaching levels of 1.65 × 10−2 mol L−1 after the synthesis with HCl at 0.50 mol L−1. Regarding yield, each ton of peanut hull produces 572.6 g of HMF, while each ton of sugarcane bagasse produces 10 kg of HMF. The calibration study using pseudo-univariate calibration models was validated by using the HPLC with relative errors lower than 15%, showing that it is possible quantify HMF and FF in the medium by using UV spectrophotometer.