Study of the change of organic matrix during the preparation of petroleum for direct spectral analysis of trace elements

The behaviour of the organic matrix, especially vanadyl porphyrins, during preparation of the petroleum sample for direct spectral analysis of traces, has been investigated. For this purpose the UV, VIS and IR spectra were used and the vanadium content was determined. It was found that decomposition of vanadyl porphyrins occurs while vanadium remains on the graphite.