Determining Collision Cross-Sections of Aromatic Compounds in Crude Oil by Using Aromatic Compound Mixture as Calibration Standard

Collisional cross section (CCS) values of a set of aromatic compounds were determined and the compounds were evaluated as standards for calibration and standardization. External calibration with poly-DL-alanine and internal and external calibration with the aromatic compounds were performed using the ion mobility mass spectra obtained from crude oils. The results showed that the external calibration method using the set of aromatic compounds is both accurate and easy to implement. The improved accuracy obtained using these aromatic standards can be explained by their greater structural similarity with the analytes in the crude oils. We anticipate that the adoption of these standards will increase the utility of IM-MS in petroleum analysis and make it easier to directly compare results from different studies.