METHOD OF SPECTROPHOTOMETRIC DETERMINING OF CONCENTRATION OF NICKEL-PORPHYRENES IN OIL OR BITUMENS UNDER PRESENCE OF VANADYLEPORPHYRENES

摘要

FIELD: geochemistry; oil chemistry. SUBSTANCE: oil or natural bitumen sample is dissolved in toluene. Optical absorption spectrum is registered at 480-650 nm range. Toluene is used as comparison solution, as well as toluene oil solution or resin-asphaltene matters, which do not contain vanadyleporphyrenes, but have absorption spectrum being closest to background absorption of sample solution. Concentration of vanadylporphyrenes is calculated from difference in optical densities at 570+-5nm at absorption and background absorption spectrum. Absorption spectrum is registered repeatedly at the same wavelength range when using oil fractions or oils as a comparison solution, which does not contain nickelporphyrenes and contains preset amount of vanadylporphyrenes and have absorption spectrum being closest to background curve of the sample tested. Concentration of nickelporphyrenes is calculated according to optical density at 550±5nm. EFFECT: improved precision. 1 dwg, 1 tbl