Direct analysis of powder samples using transversely excited atmospheric CO2 laser-induced gas plasma at 1 atm

作者：Khumaeni Ali; Lie Zener Sukra; Niki Hideaki; Kurniawan Koo Hendrik; Tjoeng Efendy; Lee Yong Inn; Kurihara Kazuyoshi; Deguchi Yoji; Kagawa Kiichiro^*

来源：Analytical and Bioanalytical Chemistry, 2011, 400(10): 3279-3287.

DOI：10.1007/s00216-011-4801-1

• Laser-induced breakdown spectroscopy (LIBS)
• Laser-induced gas plasma
• Transversely excited atmospheric CO2 laser (TEA CO2 laser)
• Direct analysis of powder sample
• Food powder sample

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) CO2 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 CO2 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.

• 出版日期2011-7