Molecular composition of vanadyl porphyrins in the gilsonite

A gilsonite from Qingchuan (Sichuan province, China) was separated into several fractions and characterized by various techniques. The vanadyl porphyrins were determined by inductively coupled plasma optical emission spectrometer, ultraviolet-visible, high-temperature gas chromatography atomic emission detection, and positive-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. The results show that the gilsonite contains a large amount of metal elements, especially the vanadium content is as high as 3888 μg/g. A large number of vanadyl porphyrins are detected, in which the deoxophylloerythroetio porphyrins are the most abundant, indicating high molecular condensation but low thermal maturity. The huge reserves and high metal content imply important utilization value for this natural source.