Affiliations: [a] Ingram School of Engineering, Texas State University, San Marcos, TX, USA | [b] Department of Biology, Texas State University, San Marcos, TX, USA | [c] Intel Inc., Austin, TX, USA | [d] Formerly Ingram School of Engineering, San Marcos, TX, USA
Correspondence:
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Corresponding author: Karl D. Stephan, Ingram School of Engineering, Texas State University, San Marcos, TX 78666, USA. Tel.: +1 512 245 3060; Fax: +1 512 245 7771; E-mail:kdstephan@txstate.edu
Abstract: OBJECTIVE: We investigate the effect of feed-gas humidity on the
oxidative properties of an atmospheric-pressure plasma jet using nitrogen
gas. BACKGROUND: Plasma jets operating at atmospheric pressure are
finding uses in medical and biological settings for sterilization and other
applications involving oxidative stress applied to organisms. Most jets use
noble gases, but some researchers use less expensive nitrogen gas. The
feed-gas water content (humidity) has been found to influence the
performance of noble-gas plasma jets, but has not yet been systematically
investigated for jets using nitrogen gas. METHOD: Low-humidity and high-humidity feed gases were used in a
nitrogen plasma jet, and the oxidation effect of the jet was measured
quantitatively using a chemical dosimeter known as FBX (ferrous
sulfate-benzoic acid-xylenol orange). RESULTS: The plasma jet using high humidity was found to have about
ten times the oxidation effect of the low-humidity jet, as measured by
comparison with the addition of measured amounts of hydrogen peroxide to the
FBX dosimeter. CONCLUSIONS: Atmospheric-pressure plasma jets using nitrogen as a
feed gas have a greater oxidizing effect with a high level of humidity added
to the feed gas.
