Method development for the determination of nickel in petroleum using line-source and high-resolution continuum-source graphite furnace atomic absorption spectrometry

Determination of Metal Ions in Crude Oils

“…Dilution with organic solvents, in spite of simplicity has number of limitations (1) Analyte concentration may change due to the evaporation of the solvent or due to the adsorption on the walls of container (Campos et al, 2002), (2) The problems of plasma destabilization or extinction in case of ICP technique and the contamination of the instrument with carbon residues persist, as the organic load is not reduced with dilution, (3) The toxicity of many organic solvents requires care to avoid and health hazard for laboratory personnel, (4) different metal -organic compounds often exhibit different sensitivity and require use of expensive organic standards for calibration (Vale et al, 2004). The standards may also show a sensitivity difference from that of the metal organic compounds present in the fuel (Teserovsky and Arpadjan, 1991).…”

“…Good agreement between found and certified results was reported. Vale et al (2004) optimized the emulsification of petroleum for the determination of the nickel. They stabilized samples and analytic solutions as an o/w emulsion consisting of xylene, Triton X-100 and water.…”

“…Burguera et al (2003) analyzed Cr in heavy crude oil and in bitumen in water emulsion by ET-AAS after sample emulsification. Vale et al (2004) optimized the determination of Ni in petroleum using both line source and high resolution continuum source ET-AAS. They stabilized sample and analyte solutions as an emulsion consisting of xylene, Triton X-100 and water.…”

Analytical Methodology for the Determination of Trace Metals in Biodiesel

“…Concentrations of Ni and Cd, and LOD and LOQ found for the samples Table 13 indicates that low limits of detection (LOD  0.85 g L -1 ) were obtained for Ni, but Ni was undetectable in the samples using this method. Many explanations can be considered, since Ni is usually present in fuels as volatile Ni and low molecular mass Ni complex (Vale et al, 2004) and may have been lost during the analyses. Low limits of detection (LOD  0.12 g L -1 ) were obtained for Cd by the analyte addition method.…”

Analyse de métaux traces dans les produits pétroliers, état de l'art

“…Vale et al (2004) montre dans sa publication que le xylène est un mauvais solvant pour le sel de Ni utilisé (acide 2-ethyl hexanoique de Ni) et s'oriente donc vers la microémulsion pour doser le Ni dans les bruts pétroliers. Un gramme de brut dilué dans 10 ml d'eau additionné de Triton X-100 permet d'obtenir une limite de détection de 70 µg/kg.…”