Effect of plasma pressure on the determination of mercury by microwave-induced plasma atomic emission spectrometry

The determination of very low levels of mercury was studied using microwave-induced plasmas (MIPs) sustained in a surfatron at reduced pressures, in the range 2–100 Torr, and at atmospheric pressure. An on-line continuous mercury cold vapour generation system was employed as the sample introduction method. Helium and argon were investigated comparatively as plasma gases. The optimization of the operating conditions, the analytical figures of merit for the determination of mercury by atomic emission spectrometry, and the effect of potential interferents such as carbon dioxide have been studied. Low pressure argon discharges proved to be superior, in terms of detection limits (DLs), to atmospheric pressure MIPs for the excitation of the atomic mercury: DLs (3s) of 0.7 pg ml–1 for a 40 Torr argon discharge and of 8 pg ml–1 at atmospheric pressure were obtained, while the DLs obtained using helium MIPs were 3 and 4 pg ml–1, respectively. Moreover, the low pressure MIPs also showed a higher resilience to the introduction of foreign gases in the discharge. A method is proposed which has been successfully applied to the determination of HgII) using a 40 Torr argon MIP.

[1]  A. Sanz-Medel,et al.  Continuous hydride generation low-pressure microwave-induced plasma atomic emission spectrometry for the determination of arsenic, antimony and selenium , 1995 .

[2]  A. Sanz-Medel,et al.  A comparative study of three microwave induced plasma sources for atomic emission spectrometry—I. Excitation of mercury and its determination after on-line continuous cold vapour generation , 1994 .

[3]  H. Matusiewicz.  Use of the Hildebrand grid nebulizer as a sample introduction system for microwave-induced plasma spectrometry , 1993 .

[4]  A. Sanz-Medel,et al.  Determination of bromide by low power surfatron microwave induced plasma after bromine continuous generation. , 1992, Talanta.

[5]  J. Carnahan,et al.  Characteristics of a Kilowatt-Plus Helium Microwave-Induced Plasma Utilizing 2- and 3-cm-Depth TM010 Resonator Cavities , 1992 .

[6]  T. Nakahara,et al.  Analyte volatilization procedure for continuous-flow determination of bromine by atmospheric pressure helium microwave-induced plasma atomic emission spectrometry , 1992 .

[7]  J. Carnahan,et al.  Atomic emission detection for supercritical fluid chromatography using a moderate-power helium microwave-induced plasma , 1992 .

[8]  M. Sáez,et al.  Determination of iodide by low power surfatron microwave induced plasma after iodine continuous generation , 1992 .

[9]  Y. Okamoto.  Annular-Shaped Microwave-Induced Nitrogen Plasma at Atmospheric Pressure for Emission Spectrometry of Solutions , 1991 .

[10]  G. Hieftje,et al.  A microwave plasma torch assembly for atomic emission spectrometry , 1991 .

[11]  G. Long,et al.  Microwave-Induced Plasma as an Elemental Detector for Packed-Column Supercritical Fluid Chromatography , 1989 .

[12]  G. Hieftje,et al.  A Low-Power Surfatron Source for the Atomic-Emission-Spectrometric Detection of Nonmetals in Aqueous Solution , 1988 .

[13]  J. Mermet,et al.  Spectroscopic evaluation of a carbon dioxide and a helium-carbon dioxide microwave-induced plasma (surfatron) , 1988 .

[14]  P. Leprince,et al.  Microwave plasma in argon produced by a surface wave: study of the effect of pressure on the optical emission and the potentials for analysis of gaseous samples , 1988 .

[15]  J. Workman,et al.  Moderate-power argon microwave-induced plasma for the detection of metal ions in aqueous samples of complex matrix , 1987 .

[16]  J. Mermet,et al.  Study of a microwave-induced plasma (surfatron) as a detector in capillary-column gas chromatography with reference to pesticides , 1987 .

[17]  R. Snook,et al.  Determination of bromide using a helium microwave induced plasma with bromine generation and electrothermal vaporisation for sample introduction , 1986 .

[18]  M. Cresser,et al.  The analysis of some diving gas mixtures by microwave-induced plasma optical emission spectroscopy , 1986 .

[19]  K. W. Baughman,et al.  Influence of pressure on the properties of a microwave-induced plasma , 1985 .

[20]  J. Broekaert,et al.  A high power microwave induced plasma for the analysis of solutions , 1984 .

[21]  G. Tölg,et al.  Three-filament and toroidal microwave induced plasmas as radiation sources for emission spectrometric analysis of solutions and gaseous samples—II. Analytical performance , 1984 .

[22]  D. C. Otto,et al.  Some fundamental measurements of the atmospheric-pressure, microwave-induced discharge , 1980 .

[23]  L. D. Galan,et al.  Improvements of the cylindrical TM010 cavity for an atmospheric pressure microwave-induced plasma , 1978 .

[24]  C.I.M. Beenakker,et al.  A cavity for microwave-induced plasmas operated in helium and argon at atmospheric pressure , 1976 .

[25]  P. Houpt.  Physical phenomena and analytical applications of helium microwave discharges , 1976 .

[26]  M. Moisan,et al.  A new HF device for the production of long plasma columns at a high electron density , 1974 .

[27]  F. Maessen,et al.  Electron temperatures and electron concentrations at low pressure in microwave induced plasmas , 1974 .

[28]  T. Vickers,et al.  Fundamental properties characterizing low-pressure microwave-induced plasmas as excitation sources for spectroanalytical chemistry , 1973 .