COVID-19 is a highly transmissible respiratory illness that has rapidly spread all over the world causing more than 115 million of cases and 2.5 million of deaths . Most epidemiological projections estimate that the SARS-CoV-2 virus causing the infection will circulate in the next few years and raise enormous economic and social issues . COVID-19 has a dramatical impact on the health care systems and patient management, and is delaying or stopping breath research activities due to the risks of infection for the operators following contact with patients, potentially infected samples or contaminated equipment . In this scenario, we investigated whether virus inactivation procedures, based on a thermal treatment (60 °C for 1 hour) or storage of tubes at room temperature for 72 hours, could be used to implement the routine breath analysis workflow allowing to carry on this activity with an optimal level of safety during the pandemic . Tests were carried out using dry and humid gaseous samples containing about 100 representative chemicals found in exhaled breath and ambient air . Samples were collected into commercially available sorbent tubes, i.e . Tenax GR and a combination of Tenax TA, Carbograph 1TD and Carboxen 1003 . Our results showed that all compounds were stable at room temperature up to 72 hours, whereas sample humidity was the key-factor affecting the stability of the compounds upon thermal treatment . Tenax GR-based sorbent tubes were less impacted by the thermal treatment, showing variations in the range 20-30% for most target analytes . A significant loss of aldehydes and sulphur compounds was observed using carbon molecular sieve-based tubes . In this case, a dry purge step before inactivation at 60 ° C significantly reduced the loss of the target analytes, whose variations were comparable to the method variability . Finally, a breath analysis workflow including a SARS-CoV-2 inactivation treatment is proposed.
Index: GC-MS, SARS-CoV-2, VOCs, breath analysis, thermal inactivation