Development of a chromatographic methodology for the separation and quantification of V, Ni and S compounds in petroleum products

Abstract : The separation, quantification and identification of V, Ni and S and their compounds in crude oils or their refining fractions is a subject of great interest for the oil industry. Such elements and heterocompounds are harmful to industry catalysts and might be toxic to living organisms. Thiswork presents amethodology based on the following two-step approach: (1) A chromatographic columnseparation is first performed on a silica gel columnto produce six fractions from the initial crude oils or petroleum products, such as vacuum residues (VRs). This separation is achieved by varying the polarity of the elution solvent systems used. (2) The separated fractions are then studied using gel permeation chromatography (GPC) coupled to an inductively coupled plasma high-resolution mass spectrometry (ICP-HRMS). Additionally, the use of ultraviolet (UV)-visible spectroscopy allows for the identification of fractions containing porphyrinic-type compounds by detecting the Soret band at 405nm. The objective of this two-step approach is to deduce both the distribution and nature of Ni and V complexeswithin the sample. This method reduces the complexity of petroleum matrices and produces simpler fractions that can be used for further studies.