title: Direct analysis of powder samples using transversely excited atmospheric CO2 laser-induced gas plasma at 1 atm.
abstract: A novel method for the direct and sensitive analysis of powder samples has been developed by utilizing the characteristics of a transversely excited atmospheric (TEA) CO(2) laser. In this study, a powder sample was placed in a container and covered by a metal mesh; the metal mesh functions to control the blowing-off of the powder. The container was then perpendicularly attached on a metal surface. When a TEA CO(2) laser (1.5 J, 200 ns) was focused on the metal surface, a large hemispherical gas plasma (radius of around 8 mm) with long emission lifetime (several tens of microseconds) was produced without ablating the metal surface. The high-speed expansion force of the gas plasma samples the powder covered by the metal mesh and fine powder particles are sent into the gas plasma region to be dissociated and excited. Sensitive semi-quantitative analysis was made on organic powder samples such as powdered rice, starch, seaweed (agar), and supplements. The detection limit of heavy metals of Cr in powdered mineral supplement was approximately 0.55 mg/kg.
authors.affiliation: Program of Nuclear Power and Energy Safety Engineering, Graduate School of Engineering, University of Fukui, Fukui, Japan.
authors.forename: Ali
authors.initials: A
authors.lastname: Khumaeni
authors.forename: Zener Sukra
authors.initials: ZS
authors.lastname: Lie
authors.forename: Hideaki
authors.initials: H
authors.lastname: Niki
authors.forename: Koo Hendrik
authors.initials: KH
authors.lastname: Kurniawan
authors.forename: Efendy
authors.initials: E
authors.lastname: Tjoeng
authors.forename: Yong Inn
authors.initials: YI
authors.lastname: Lee
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kurihara
authors.forename: Yoji
authors.initials: Y
authors.lastname: Deguchi
authors.forename: Kiichiro
authors.initials: K
authors.lastname: Kagawa
mesh_terms: D002857:Chromium / Q000032:analysis; D019587:Dietary Supplements / Q000032:analysis; D005504:Food Analysis; D007834:Lasers; D057230:Limit of Detection; D019216:Metals, Heavy / Q000032:analysis; D012275:Oryza / Q000737:chemistry; D011208:Powders / Q000032:analysis*; D011312:Pressure; D012624:Seaweed / Q000737:chemistry; D013213:Starch / Q000032:analysis
chemical_list: D019216:Metals, Heavy; D011208:Powders; D002857:Chromium; D013213:Starch