Role of Metastable and Spore Hydration to Sterilize Spores by Nitrogen Gas Plasma Exposure and DPA Analysis by HPLC Combined with UV Detection

Many papers have been published on gas plasma sterilization. They are mostly conducted by physical researchers, so microbiology and chemical aspects are significantly insufficient. By joining the biologists and chemists, gas plasma sterilization research was outstandingly advanced. The sterilization mechanism by gas plasma was not clarified until now and from the life time and some other reasons metastables or photon can be the most appropriate candidate for sterilization. Spore death is explained from the hydration of dipicolinic acid in the core. By attacking the spores with metastables or photons, it produced pin hole and the interior water and surrounding water penetrate into the core to hydrate DPA. DPA in the surface was collected with water and enriched with SPE (solid phase extraction) column. SPE drain was analyzed with C-18 HPLC column and eluted with an acetonitrile/water (1/4, v/v, pH5) and detected at 235nm. From the coincidence of retention time of the studied target and that of standard substance, spore surface particle can be confirmed DPA. The hydration process can cause within the spore, so spore figures are unchanged before and after sterilization. *Corresponding author: Hideharu Shintani, Chuo University, School of Science, 1-13-27, Kasuga Bunkyo 112-0003, Tokyo, Tel: +81425922336, E-mail: [email protected]