TITLE:
Microwave-Assisted Inactivation of Fomite-Microorganism Systems: Energy Phase-Space Projection
AUTHORS:
Victor J. Law, Denis P. Dowling
KEYWORDS:
Bacteria, MS2, Hepatitis C Virus, Human Immunodeficiency Virus, Influenza Virus, Disruption, Inactivation, Microwave Oven, Data Analysis
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.13 No.7,
July
28,
2022
ABSTRACT: This paper describes the use of log-linear energy phase-space projections to analyze microwave-assisted inactivation of bacteria and viruses under different fomite conditions within multimode microwave ovens. The ovens are operated at a cavity-magnetron frequency of 2.45 ± 01 GHz. Porous fomites (moist face towels, cotton swabs, kitchen sponges, and scrubbing pads, cigarette filters and N95-like respirators); along with non-porous hard surface syringe fomites are studied. The fomites are classed as dielectric; and absorb microwave energy to varying degrees depending on their complex dielectric permittivity. Microorganism resilience to microwave stress (defined as ≥4 log10 reduction in inactivation) when mapped using iso-volume trend-lines in energy phase-space reveals the persistence imparted by the fomite, and can be mapped between different microwave ovens. Microorganism resilience to thermal microwave-assisted treatment increases from vegetative Gram-negative to vegetative Gram-positive and on to Gram-positive spores. Bacteriophage MS2 and influenza viruses have an intermediate resilience dependency. It is shown that linear-scaled fomite temperature against process time graphs can differentiate between non-thermal and thermal micro-wave-assisted treatment of microorganisms.