A Comparison of Measurement Methods for Alcohol-Based Hand Sanitizers
Mary Bedner, Jacolin Murray, Aaron A. Urbas, William A. MacCrehan, Walter Brent Wilson
The production and demand for hand sanitizers have increased dramatically during the coronavirus disease 2019 (COVID-19) health emergency. To be deemed effective and safe, hand sanitizers should contain at least 60 % alcohol (typically ethanol) as well as minimal amounts of harmful impurities regulated by the Food and Drug Administration (FDA). To help ensure product potency and safety through sound measurements, the National Institute of Standards and Technology (NIST) developed and evaluated four instrumental measurement approaches for their applicability in measuring ethanol and impurities in 72 hand sanitizers representing a range of brands and formulations. The methods included gas chromatography with flame ionization detection (GC-FID), liquid chromatography with ultraviolet absorbance detection (LC-UV), quantitative nuclear magnetic resonance spectroscopy (qNMR), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). All four instrumental methods can determine and provide comparable results for ethanol, the principle disinfectant in different hand sanitizer formulations. All methods can also confirm the presence of other alcohols potentially present in significant quantities (≈ percent levels) such as methanol, a harmful impurity, and isopropanol, which can be either the primary disinfectant or an approved denaturant in some formulations. Two of the methods, qNMR and GC-FID, were also able to determine impurities at the requisite sensitivity levels (µg/g) set by the FDA limits. This report presents descriptions and key results from each method. In addition, a discussion regarding the applicability and strengths and weaknesses of each measurement approach for the analysis of hand sanitizers is presented and discussed.
, Murray, J.
, Urbas, A.
, MacCrehan, W.
and Wilson, W.
A Comparison of Measurement Methods for Alcohol-Based Hand Sanitizers, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.IR.8342, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=931548
(Accessed October 23, 2021)