Determination of Total Nickel and Vanadium and Their Volatile and Thermally Stable Species in Crude Oil Using High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry

The ‘visibility’ of the spectral vicinity of the analytical line at high resolution and the hitherto unattained performance of the truly simultaneous background correction are outstanding features of high-resolution continuum source atomic absorption spectrometry (HR-CS AAS). A potential source of error in the analysis of crude oil using graphite furnace AAS (GF AAS) was discovered with the aid of this technique. Part of the organic nickel and vanadium compounds (porphyrins) is volatile already at temperatures above 400°C and can be lost in the pyrolysis stage, whereas the salt-like, polar compounds of both elements are thermally stable up to 1300°C and 1600°C, respectively. HR-CS GF AAS also makes possible determining volatile and non-volatile species separately, which significantly increases the information content of the analyses.