On‐column atomic emission detection in capillary gas chromatography using a radio frequency plasma

Abstract

Abstract. Detection limits of heteroatoms and carbon were improved by eliminating the make-up gas and sustaining a 350 kHz radio frequency plasma inside the end of a fused silica gas chromatography (GC) column (0.32 mm i d . ) for capillary GC with atomic emission detection. Due to the small internal diameter of the plasma cell, a stable plasma was maintained in only 1.5-3 mL min" of heliumused as the GC carrier gas. The optical system consisted of a single low resolution monochromator for the near-infrared region in order to develop a simple and low-cost system. For on-column detection of C, H, S, CI, Br, and I, the plasma was doped with traces of oxygen. The oxygen dopant served to suppress peak tailing and to maintain high selectivity and repeatability. Detection limits for C, H, S, C1, Br, and I ranged from 0.9 to 11.8 pg s-', and selectivities between 4x I d and 4 x I d were obtained. On-column F-selective detection required a plasma doped with a mixture of hydrogen and oxygen. The detection limit for F was 13.0 pg s-'; however, the selectivity was poor (10) due to the low resolution of the spectrometer.

Sample Analysis with Miniaturized Plasmas

“…The RFP was further miniaturized by Pedersen-Bjergaard et al 37,38 and is shown in Fig 6. A 5 cm long piece of polyimide coating and the stationary phase were carefully burned off at the end of a fused silica GC column. The last 2 cm of this uncoated GC capillary served as the plasma tube and was placed inside a piece of silica tube for protection.…”

Analytical Detectors Based on Microplasma Spectrometry

“…This detector was found to have low limits of detection of sulfur (0.5 pg/s) and a good linear response (four decades). This plasma was further miniaturized by Pedersen-Bjergaard et al [24,25] and is shown in Fig. 5.…”

Microplasma-Based Detectors for Gas Chromatography: Current Status and Future Trends

“…A stable plasma was maintained with a helium flow rate of only 1.5-3 mL min −1 . The detection limits of halogens, carbon, hydrogen, and sulfur ranged from 0.9 to 13.0 pg s −1 with strong emission lines (44). The detector was also used for the practical detection of bromine and chlorine in drinking Downloaded by [Lakehead University] at 10:23 08 December 2014 water on an oil-drilling platform and for the analysis of polyhalogenated compounds in environmental samples (45).…”