Automating the NMR analysis of base oils: Finding napthene signals

Base oils, as many other oil products, are mainly analyzed with dedicated techniques designed to characterize the performance of these products in their intended use, along with suitable analysis techniques such as MS or GC to provide basic chemical information about the constituents. However, the physicochemical properties of base oils are direct result of the chemical structures of the molecules present in the oil, from which these techniques provide limited information. NMR spectroscopy, while more complex and expensive than many other analysis techniques, provides unique insight to the chemical structures present in these complex hydrocarbon mixtures. Utilizing NMR for analysis of base oils is not straightforward, and in this paper we go through this process and demonstrate how our software designed for mass analysis of quantitative spectra (ImatraNMR) can be used to automate the analysis, especially with novel addition of SimpeleNMR processing software. Additionally, ImatraNMR and a novel 2D version of Q-INEPT-CT experiment are used to conduct statistical correlation analysis aiming to detect signals originating from napthene (cycloalkane) structures present in base oil samples.