Abstract
The spectrophotometric studies of vanadylporphyrin complexes isolated from the oil of the Severnoe Buzachi field with absorption maxima at 534 and 573 nm showed that the dominant compounds were etioporphyrins (ETIOs) and deoxophylloerythro-etioporphyrins (DPEPs), and that extraction with N,N-dimethylformamide allows extraction of vanadylporphyrin complexes from oil without destroying their structure. The ETIO/DPEP ratio of vanadylporphyrins was 1.14–2.17. The IR spectra of the isolated vanadylporphyrin fractions indicated that the content of free porphyrins was extremely low judging by the presence of deformation and out-of-plane vibrations of the NH group in the ranges 3250–3400 and 960–980 cm –1 . This suggests that the extraction method for isolating vanadylporphyrins does not lead to their demetallization. The EPR spectral data confirmed the high concentration and purity of vanadylporphyrin, which correlates well with the UV spectral data and indicates that chromatographic purification and separation of the extract is efficient.