Production of active species in N₂–O₂flowing post-discharges at atmospheric pressure for sterilization

Abstract

A flowing afterglow of very pure molecular nitrogen at atmospheric pressure with admixture of controlled amounts (from some tens to some thousands ppm) of molecular oxygen is studied. For flows of 40 slm, spectroscopic measurements down the discharge allow us to estimate concentrations in atomic nitrogen and in singlet-S metastable oxygen atoms. With UV emission due to nitrogen oxide, all three reactive agents exhibit sporicidal effects, and their relative role is estimated.

A comparison of plasma and electron beam-sterilization of PU catheters

“…A significant amount of atomic nitrogen was produced and propagated over a long distance (Larbre et al, 2004). It was thus able to decontaminate surfaces in the afterglow area (Pointu et al, 2005). Three 30 cm-long catheters were treated together, in such a way that only the external surface was exposed to plasma and treated.…”

Emission spectroscopy of atmospheric pressure plasmas for bio-medical and environmental applications

“…This enables understanding and optimizing the air or water pollution control processes. Identification of radicals is also of great importance in biological and medical applications in order to understand the mechanisms of bio-inactivation and of the plasma interaction with living cells [3,4]. Excited states are produced mostly by collisions with energetic electrons, and therefore it is assumed that optical emission can provide a measurement of the plasma active size.…”

Afterglow corona discharge air plasma (ACDAP) for inactivation of common food-borne pathogens

“…Plasma/air mixture predominantly consists of nitric oxide (NO) as reactive chemical species besides oxygen (20.9%); and minute quantities of nitrogen dioxide (NO 2 ) and carbon monoxide were detected. According to another study, reactive species such as atomic nitrogen, singlet-S metastable oxygen, UV emission due to nitrogen oxide are the major ones in a flowing afterglow of very pure nitrogen with admixture of controlled amounts of molecular oxygen (Pointu et al, 2005). A complete chemical characterization of ACDAP will be required to determine the role of other reactive species in inactivation.…”