P. Sassiat et al., LIQUID-CHROMATOGRAPHIC DETERMINATION OF BASE OIL COMPOSITION AND CONTENT IN LUBRICATING OILS CONTAINING DISPERSANTS OF THE POLYBUTENYLSUCCINIMIDE TYPE, Analytica chimica acta, 306(1), 1995, pp. 73-79
The determination of base oil composition and content in engine motor
oils and in the fractions enriched in the polybutenylsuccinimide type
dispersant which can be isolated from the lubricants are achieved thro
ugh liquid chromatography. Strongly activated silica gel and anhydrous
pentane are used associated with a backflush technique and refractome
tric detection. Calibration is done with Neutral 200 base oil whose co
mposition is determined by mass spectrometry. It is shown that the tre
atment of multigrade motor oils through dialysis and classical liquid
adsorption chromatography on a Florisil column leads to a dispersant w
ithout appreciable content of base oil.