Determination of active ingredients in alcohol‐based gel by spectroscopic techniques and chemometric analysis

The international public health emergency related to COVID-19 caused by the SARS-CoV-2 virus has altered several production and registration criteria for sanitary products, including alcohol-based hand sanitizers. In this work, we investigate the concentration of alcohol in sanitizers presented in gel form applying the principal component regression method on measurements using Infrared and Raman spectroscopic methods. The chemometric calibration is performed using isopropanol or ethanol as active agents, and the method is used to characterize several commercial samples. Furthermore, the results of the prediction of alcohol concentration, obtained by applying the principal component regression and partial least squares methods, in the spectroscopic techniques, were compared with each other and with the results provided by nuclear magnetic resonance. Our results show that spectroscopic techniques coupled with principal component regression are fast, low-cost, and safe tools for the determination of alcohol concentration, regardless the gelling agent used.