PROXIMATE METHOD FOR DETERMINING PETROPORPHYRINS CONCENTRATION IN RAW OIL Russian patent published in 1996 - IPC

FIELD: geology. SUBSTANCE: method involves separating oil samples by means of adsorption chromatography method on silica gel ASKG into three fractions. Fraction solutions are examined by means of stectrophotometer in the range of 450-650 nm to calculate nickel and vanadyl porphyrins contents from adsorption band intensity at 550 ± 5 and 570 + 5 nm, respectively. The first fraction of a sample is desorbed by 150-250 ml of CCl₄:C₆H₁₄ mixture in 85:15-95:5, the second one is desorbed by 150 ml of CCl₄:C₆H₆ mixture in 45:55-55:45 and the third one is desorbed by 300 ml of C₆H₆:C₂H₅OH mixture in 55:50 proportion. The second fraction is nickel porphyrin concentrate, the third one is vanadyl porphyrin concentrate. Petroporphyrin contents in a fraction being low, the sample is treated in spectrophotometer using special reference solutions having spectral curve most closely approximating in shape the background curve of the fraction under analysis. EFFECT: enhanced accuracy of the method. 2 cl, 1 dwg