Development of a portable optical device with a multi-channel spectrometer sensor for quantification of glycerol in wine: a maker approach for on-site analysis

Abstract

In this work we present a novel and environmentally friendly approach for quantifying glycerol in wine samples using a portable optical device based on the maker concept and do-it-yourself (DIY) principles. This method offers significant advantages, including cost-effectiveness, reduced sample and reagent consumption, and the potential for integrating IoT (Internet of Things) technology. The chemical strategy involves the oxidation of glycerol using periodate, followed by the formation of the 3,5-diacetyl-1,4-dihydrolutidine (DDL) compound through a reaction with acetylacetone. The utilization of a cost-effective AS7341 color sensor as a detector enables accurate and sensitive detection of glycerol levels in wine samples. The optimized procedure demonstrates adequate analytical performance for glycerol determination in wine samples, encompassing a wide linear range (0.5 mg L⁻¹ to 40.0 mg L⁻¹), high correlation coefficient (r = 0.998), and low limits of detection (0.050 mg L⁻¹). The method exhibits excellent precision, with the coefficient of variation estimated to be 0.1% for 10 independent measurements of a 20 mg L⁻¹ solution. These features render it suitable not only for routine glycerol analysis in the wine industry, but also for addressing challenges related to wine adulteration and counterfeiting.