Precision in Petroleomics via Ultrahigh Resolution Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

The ultrahigh resolution and mass accuracy of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with the aid of soft ionization techniques, such as electrospray ionization (ESI), have been shown to provide fast and comprehensive class composition information of crude petroleum samples and distillates. This information has been translated into the major geochemical properties of the oil, but the level of reliability of the petroleomic approach by FT-ICR MS to compare samples or to predict sample characteristics remains an open question. To access this fundamental figure of merit, we have studied the repeatability and reproducibility of the ESI FT-ICR MS petroleomic method by using representative samples analyzed by different analysts and laboratories. In addition, the mean compatibility of the relative ion abundance obtained by two similar 7.2 T instruments located in different laboratories was evaluated. The data were analyzed via statistics tools, such as analysis of variance (ANOVA) to evaluate the repeatability and reproducibility among days and analysts, paired Student’s t-test to compare the means obtained from different laboratories among different typical samples, and control charts to monitor the analytical system. A high degree of precision in petroleomic studies by FT-ICR MS has been found, particularly for the most abundant classes of components and, hence, for the classes currently used for property evaluation.