Investigating the Use of SARS-CoV-2 (COVID-19) Odor Expression as a Non-Invasive Diagnostic Tool-Pilot Study.

Since the beginning of the COVID-19 pandemic, there has been enormous interest in the development of measures that would allow for the swift detection of the disease. The rapid screening and preliminary diagnosis of SARS-CoV-2 infection allow for the instant identification of possibly infected individuals and the subsequent mitigation of the disease spread. Herein, the detection of SARS-CoV-2-infected individuals was explored using noninvasive sampling and low-preparatory-work analytical instrumentation. Hand odor samples were obtained from SARS-CoV-2-positive and -negative individuals. The volatile organic compounds (VOCs) were extracted from the collected hand odor samples using solid phase microextraction (SPME) and analyzed using gas chromatography coupled with mass spectrometry (GC-MS). Sparse partial least squares discriminant analysis (sPLS-DA) was used to develop predictive models using the suspected variant sample subsets. The developed sPLS-DA models performed moderately (75.8% (±0.4) accuracy, 81.8% sensitivity, 69.7% specificity) at distinguishing between SARS-CoV-2-positive and negative -individuals based on the VOC signatures alone. Potential markers for distinguishing between infection statuses were preliminarily acquired using this multivariate data analysis. This work highlights the potential of using odor signatures as a diagnostic tool and sets the groundwork for the optimization of other rapid screening sensors such as e-noses or detection canines.

The Use of Biological Sensors and Instrumental Analysis to Discriminate COVID-19 Odor Signatures.

The spread of SARS-CoV-2, which causes the disease COVID-19, is difficult to control as some positive individuals, capable of transmitting the disease, can be asymptomatic. Thus, it remains critical to generate noninvasive, inexpensive COVID-19 screening systems. Two such methods include detection canines and analytical instrumentation, both of which detect volatile organic compounds associated with SARS-CoV-2. In this study, the performance of trained detection dogs is compared to a noninvasive headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) approach to identifying COVID-19 positive individuals. Five dogs were trained to detect the odor signature associated with COVID-19. They varied in performance, with the two highest-performing dogs averaging 88% sensitivity and 95% specificity over five double-blind tests. The three lowest-performing dogs averaged 46% sensitivity and 87% specificity. The optimized linear discriminant analysis (LDA) model, developed using HS-SPME-GC-MS, displayed a 100% true positive rate and a 100% true negative rate using leave-one-out cross-validation. However, the non-optimized LDA model displayed difficulty in categorizing animal hair-contaminated samples, while animal hair did not impact the dogs' performance. In conclusion, the HS-SPME-GC-MS approach for noninvasive COVID-19 detection more accurately discriminated between COVID-19 positive and COVID-19 negative samples; however, dogs performed better than the computational model when non-ideal samples were presented.

Volatile Chemical Profile of Ethanol-based Hand Sanitizer Marketed in Brazil by HS-SPME/GC-MS

Aims: This study aims to determine the volatile chemical profile of ethanol-based hand sanitizer marketed in Brazil by HS-SPME/GC-MS. Background: Ethanol-based hand sanitizer has been used to protect against coronavirus disease (COVID-19). In general, these formulations are prepared using a carbomer. In 2020 and 2021, the production of hand sanitizer has increased due to the COVID-19 epidemic. Therefore, it is important to know the composition of this formulation because certain molecules present in some alcoholic mixtures can cause health problems. Methods: Ethanol-based hand sanitizer, AL1, AL2, BL1, CL1, DL1, EL1, FL1, and GL1 (ethanol derivative of fuel station), was purchased from manufacturers commercialized in Araguaína-TO and analyzed by HS-SPME/GC-MS for determining volatile chemical profile. Results: The analyses showed different compositions for the ethanol-based hand sanitizers. Samples AL1 and AL2 contained isopropyl alcohol, ethyl acetate, benzene, ethane-1,1-diethoxy, limonene, and other compounds. Linear alkanes were also detected. Only ethyl acetate and ethane-1,1-diethoxy were detected in CL1, in addition to ethanol. Thus, it is the most suitable sample among those analyzed. The presence of benzene, alkanes, and other hydrocarbons may be associated with the use of fuel ethanol to prepare these sanitizers, as shown in the sample GL1. Benzene, xylene, and toluene were found in FL1. This sample is the most contaminated among those analyzed. Conclusion: The chemical profile of commercial ethanol-based hand sanitizer from eight different samples sold in Araguaína-Brazil was established by GC-MS. Compounds like benzene and other alkanes were found in some samples. These results suggested possible contamination by alcohols unqualified in producing pharmaceutical substances. These analyzes are particularly relevant due to the pandemic situation to avoid COVID-19 proliferation. Benzene and other alkanes are harmful to human health and should be avoided in hand sanitizer production.