Scientists at the University of Warwick have developed a more powerful method of analyzing chemical mixtures, which can assign 244,779 molecular compositions within a single sample of petroleum, according to the university. With almost a quarter-million individual compositions assigned within a non-distillable fraction of crude oil, the new method developed by the Barrow Group within the Department of Chemistry and detailed in a paper for the journal Chemical Science, paves the way for analysis of challenging samples across different fields. Assigning the compositions of molecules in a complex mixture is valuable tool for a number of industries, where determining the elemental composition of those molecules can provide valuable data for research, determine the mixture’s viability such as in the petrochemical industry or even ‘fingerprint’ a complex mixture such as oil or environmental samples.
The researchers developed a new method called operation at constant ultrahigh resolution (OCULAR) that combines experimental and data processing techniques and allows them to characterize the most complex sample they have ever worked on. Using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the researchers analyzed a sample of heavy petroleum in solution. The molecules in the sample were then ionized, excited and detected to determine the mass-to-charge ratios using a solariX (Bruker Daltonics) FT-ICR mass spectrometer. The ultrahigh resolving power and mass accuracy of FT-ICR MS allows the scientists to determine the elemental compositions within even the most complex samples with a high degree of confidence.
Traditional analysis performed with a variety of Fourier transform mass spectrometers (FTMS) offers decreasing resolving power and confidence in assignments of the elemental compositions at higher m/z when studying a broad m/z range. In the new OCULAR method, ions are analyzed using smaller data segments based upon their mass, where the experiment is designed in a way to ensure almost constant resolving power across the full mass range analyzed.
The technique can be used for any analysis of a complex mixture and has potential applications in areas such energy (e.g. petroleum and biofuels), life sciences and healthcare (e.g. proteomics, cancer research and metabolomics), materials (e.g. polymers) and environmental analysis, including being used to “fingerprint” oil spills by their molecular composition.
For more information, visit: www.warwick.ac.uk