Greener method proposal for the determination of phenolic compounds and coumarins in aged sugarcane spirits using green bio-based solvents in HPLC-DAD-FLD system

Abstract

High Performance Liquid Chromatography (HPLC) has been the most used analytical technique for analyzing phenolic compounds and coumarins in aged sugarcane spirit samples. It requires a significant amount of organic solvents, often toxic, as the mobile phase. The use of green bio-based solvents is a good alternative in the implementing more eco-friendly methods. Therefore, this work aims to propose a greener chromatographic method for the determination of phenolic compounds and coumarins in sugarcane spirit samples aged in different woods, using bio-based organic solvents (ethanol and acetic acid) in HPLC system with diode array and fluorescence detectors. Different metric tools (AGREE, ComplexMoGAPI, BAGI and Analytical Eco-scale) were used to evaluate the greenness of the analytical method. The proposed method was rigorously validated: linearity (R2 ≥ 0.9901); LOD (0.05 to 0.55 mg l-1); LOQ (0.25 to 5.00 mg l-1); precision (0.13 % ≤ RSD ≤ 18.6 %). The concentrations of total phenolic compounds and coumarins were up to 7.22 mg l-1. The sugarcane spirit aged in umburana presented the highest concentration of total phenolic compounds and coumarins with emphasis on trans-cinnamic acid (4.74 ± 0.01 mg l-1) and catechin (1.22 ± 0.02 mg l-1). All samples presented coumarin concentrations (<5.00 mg l-1) within the limit acceptable by legislation (10 mg l-1). The AGREE score (0.72) showed that the proposed method was greener and sustainable compared to other methods. The application of new mobile phase using green bio-based solvents proved to be advantageous from a Green Analytical Chemistry point of view.