Determination of Viscosity Improvers and Detergent Additives in Synthetic Motor Oils by Gel Permeation Chromatography

We proposed a procedure for the simultaneous determination of viscosity improvers and detergent additives in synthetic oils by gel permeation chromatography, including the preliminary liquid extraction of polar additives, solid-phase extraction of polymer additives on silica modified with magnesium oxide from oil raffinate, and the subsequent determination of analytes. The procedure was used to determine viscosity improvers and detergent additives in fresh and used synthetic motor oils, to control the quality of oils at different stages of operation, and to monitor the degree of purification of oils during their regeneration. In-process monitoring of additive concentrations during the operation of automotive equipment enables the timely control of the dynamics of engine oil degradation throughout its use and proper recommendations for its replacement in the system. The procedure was tested in the analysis of fresh and used multigrade synthetic motor oils Shell Helix Ultra 5W-30 and TP MAX Total 10W-40 and fresh multigrade synthetic motor oil Shell Rimula R5M 10W-40.