Zeolite Slurry Analysis Using Freon-Assisted Graphite Furnace Vaporization for Inductively Coupled Plasma Atomic Emission Spectrometry

Abstract

Halogen-assisted electrothermal vaporization (ETV) was used as a sample introduction mechanism for inductively coupled plasma atomic emission spectrometry. Freon-12™ was used as a gas-phase halogenation reagent in the ETV graphite furnace to enhance vaporization of carbide-forming elements by converting them into metal halides. With Freon ETV, detection levels for Zn, Pb, Cd, Mn, V, Cu, Ti, and Ca were lower than those obtained with conventional nebulization of liquid standards. A zeolite sample was analyzed for the refractory elements chromium and vanadium. Without Freon, the signals for these elements were very low; however, with Freon, the signals were dramatically improved. Detection limits of 1.4 μg/g and 0.3 μg/g, respectively, were obtained for these elements. A sheathing and cooling gas flow was introduced to reduce analyte vapor condensation on tubing walls and to promote aggregate formation. This additional flow enhanced the quality of signal with the zeolite but proved to be detrimental for the determination of refractory elements in liquid standards with or without halogenation. The precision of determination for the zeolite sample varied from 3% for cadmium, to 6% for lead.

Determination of titanium by slurry sampling graphite furnace atomic absorption spectrometry with the use of fluoride modifiers

“…Determination of titanium by slurry sampling graphite furnace atomic absorption spectrometry with the use of fluoride modifiers (ICP-MS) [8,9,10,11,12,13,14,15,16,17]; halogenassisted volatilization, that is, in situ formation of volatile halides of the analytes in the graphite furnace, has been shown to enhance the sensitivity, reduce the memory effect, and improve the limit of detection for many carbideforming elements.…”

“…Fluor-assisted vaporization has successfully been used for determination of Ti by ETV-ICP-OES/MS; the fluorination agents that have been used are polytetrafluoroethylene (PTFE) [10,13,15,17], CF 2 Cl 2 (Freon-12) [11], NH 4 F [17], NaF [17], and CuF 2 ·2 H 2 O [17]. A condition for these modifiers to function as intended in GFAAS, which does not apply to ETV-ICP, is that the formed fluorides are decomposed/atomized before leaving the furnace.…”

Vaporization and removal of silica for the direct analysis of geological materials by slurry sampling electrothermal vaporization-inductively coupled plasma-mass spectrometry

“…Kirkbright and Snook 12 used 0.1% freon-23 for the determination of B, Mo, Zr, Cr and W, 13 and CCl 2 and freon-12 to determine trace elements in ceramic powders and SiC. 14 Ren and Salin 15,16 and Allary et al 17 used freon-12 to enhance the vaporization of carbide forming elements. Matousek et al 18 used Cl 2 for the determination of Cr, V, Ti, W, and Zr.…”

Improved Slurry Sampling Electrothermal Vaporization System Using a Tungsten Coil for Inductively Coupled Plasma Atomic Emission Spectrometry

“…The average particle diameter was 0.48 mm with a Gaussian grain size gaining popularity for the direct determination of impurities in solids at the trace or ultratrace level. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] distribution; 90% of the sample had a particle diameter of about 0.80 mm. Graphite furnaces similar to those used in atomic absorption spectrometry (AAS) are the predominant type of ETV Working standard solutions were prepared using single element stock standard solutions (1 g l−1) (Merck, Darmstadt, devices.…”

“…Graphite furnaces similar to those used in atomic absorption spectrometry (AAS) are the predominant type of ETV Working standard solutions were prepared using single element stock standard solutions (1 g l−1) (Merck, Darmstadt, devices. [1][2][3][4][5][6][7][8][9][10][11][20][21][22][23][24][25] Besides graphite, refractory metals (tungsten or tantalum tubes and filaments) have been used as furnace Germany). For dilution of the stock standard solutions and preparation of the sample slurries, doubly distilled water was materials.14,26-30 Double-layer tungsten coils normally manufactured in large numbers for low-voltage lamps also belong used.…”