Characterization of diesel fuel by chemical separation combined with capillary gas chromatography (GC) isotope ratio mass spectrometry (IRMS)

► A need exists to distinguish diesel fuels having near-identical chromatographic profiles. ► Compound-specific isotope ratio analysis has potential to differentiate fuels. ► Plots of hydrogen versus carbon isotope ratios for n-alkanes gave unique fuel-specific plots. ► Principal components analysis (PCA) of combined isotope data gave clear differentiation of fuels. ► Nearest neighbor classification of PCA scores gave near-perfect classification.