Quantifying ethanol in ethanol-based hand sanitizers by headspace gas chromatography with flame ionization detector (HS-GC/FID)

Background The COVID-19 pandemic sharply increased the demand for ethanol-based gel hand sanitizers, leading to a shortage of these products. Consequently, regulatory health agencies worldwide have altered their regulatory guidelines, on ethanol quality, to meet this high demand, raising concern about the products quality. Objective The aim of this study was to quantify ethanol content and to qualitatively assess common impurities in ethanol-based gel hand sanitizers by headspace gas chromatography with flame ionization detector (HS-GC/FID). Methods To quantify the ethanol content, 0.10 g of the sample was weighed in a 20 mL headspace vial and 5 mL of deionized water was added. Regarding the qualitative approach, 0.25 g of the sample was weighed and 4 mL of deionized water and was added. The samples were incubated, and then 400 µL of the headspace was injected into the GC/FID. Forty-eight products purchased in Brazil were analyzed. Results Thirteen products presented at least one nonconformity regarding the ethanol quantity. Two samples presented an average ethanol concentration below the lower limit considered effective. Twelve samples presented acetaldehyde or ethyl acetate. Conclusion The huge demand for ethanol-based gel hand sanitizers may have impacted their quality. Because concern with proper hand hygiene tends to remain an issue for a long period, more studies about quality control of hand sanitizers will be needed. Highlights A simple and fast HS-GC/FID method to quantify ethanol in ethanol-based gel hand sanitizers was developed, validated and applied to commercial samples in Brazil. The regulatory authorities must be more vigilant to ensure that the commercially available products meet the recommended specifications.