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 concerns about product 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 (HS) gas chromatography (GC) with flame ionization detector (FID). METHODS: To quantify the ethanol content, 0.10 g of the sample was weighed in a 20 mL HS 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 was added. The samples were incubated and then 400 µL of the HS 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.

Application of microextraction techniques in alternative biological matrices with focus on forensic toxicology: a review.

The interest in alternative biological matrices (e.g., hair and saliva) for forensic toxicology analysis has increased, and recent developments in sample preparation have targeted rapid, cheap, efficient and eco-friendly methods, including microextraction techniques. For this review, we have gathered information about these two hot topics. We discuss the composition, incorporation of analytes and advantages and disadvantages of different biological matrices, and also present the operation principles of the most reported microextraction procedures and their application in forensic toxicology. The outcome of this review may encourage future forensic researches into alternative samples and microextraction techniques.