Rigaku NEX QC+ EDXRF method for elemental analysis of S, V, Ni in crude oil

Applied Rigaku Technologies has published an application report that details the analysis of sulfur, vanadium and nickel in crude oil using the Rigaku NEX QC+ energy dispersive X-ray fluorescence (EDXRF) analyser. The report includes information about sample preparation, method calibration and repeatability.

Sulfur (S), vanadium (V) and nickel (Ni) occur naturally in crude oil, but their concentrations vary depending on the geographical region of the oil deposits. Vanadium and nickel can taint the refining process during crude oil cracking, thereby making crude oil with low levels of vanadium and nickel advantageous. In oil fields and off-shore wells, a quick and easy means of screening for vanadium and nickel is essential for characterising the quality of the crude prior to refining. Rigaku fulfils such analytical industry requirements with the NEX QC series of EDXRF analysers.

Empirical calibrations were built using a suite of 10 commercially available mineral oil calibration standards, and two calibration standards were measured in 10 repeat analyses to demonstrate precision. Analysis was performed using the Rigaku NEX QC+ high-resolution benchtop EDXRF analyser, optimised for rapid qualitative and quantitative elemental analysis.

The spectra presented demonstrate the multielement capability of the spectrometer for analysing crude oils and show good sensitivity and detection limits for the critical elements. Fast and simple, the analyser is a suitable tool for monitoring the concentrations of vanadium and nickel in crude, as well as the sulfur content, enabling thorough evaluation of the quality of the refining process.