Use of xerogels for the elemental analysis of crude oils by laser ablation inductively coupled plasma high resolution mass spectrometry

A novel method for the preparation of crude oil samples based on a xerogel matrix was developed for elemental analysis using laser ablation–double focusing sector field inductively coupled plasma-mass spectrometry. The samples and aqueous solution were successfully encapsulated using zirconium n-propoxide. The use of xerogel produces stable and homogeneous pellets, avoids splashing of the sample and allows the use of aqueous inorganic standards to elaborate the calibration curve. Sulfur, nickel and vanadium were selected as test elements and indium was used as the internal standard to correct the variations in the amount of material ablated. The correlation coefficients of the calibration curves for all the elements tested were better than 0.990 except for sulfur. Crude oil results showed no significant statistical differences between the sol–gel results and those obtained with similar studies.