title: Predicting percent composition of blends of biodiesel and conventional diesel using gas chromatography-mass spectrometry, comprehensive two-dimensional gas chromatography-mass spectrometry, and partial least squares analysis.
abstract: The percent composition of blends of biodiesel and conventional diesel from a variety of retail sources were modeled and predicted using partial least squares (PLS) analysis applied to gas chromatography-total-ion-current mass spectrometry (GC-TIC), gas chromatography-mass spectrometry (GC-MS), comprehensive two-dimensional gas chromatography-total-ion-current mass spectrometry (GCxGC-TIC) and comprehensive two-dimensional gas chromatography-mass spectrometry (GCxGC-MS) separations of the blends. In all four cases, the PLS predictions for a test set of chromatograms were plotted versus the actual blend percent composition. The GC-TIC plot produced a best-fit line with slope=0.773 and y-intercept=2.89, and the average percent error of prediction was 12.0%. The GC-MS plot produced a best-fit line with slope=0.864 and y-intercept=1.72, and the average percent error of prediction was improved to 6.89%. The GCxGC-TIC plot produced a best-fit line with slope=0.983 and y-intercept=0.680, and the average percent error was slightly improved to 6.16%. The GCxGC-MS plot produced a best-fit line with slope=0.980 and y-intercept=0.620, and the average percent error was 6.12%. The GCxGC models performed best presumably due to the multidimensional advantage of higher dimensional instrumentation providing more chemical selectivity. All the PLS models used 3 latent variables. The chemical components that differentiate the blend percent compositions are reported.
authors.affiliation: Department of Chemistry, Seattle Pacific University, 3307 Third Avenue West, Suite 205, Seattle, WA 98119-1950, USA. pierck1@spu.edu
authors.forename: Karisa M
authors.initials: KM
authors.lastname: Pierce
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Schale
mesh_terms: D056804:Biofuels / Q000032:analysis*; D002138:Calibration; D005591:Chemical Fractionation; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D005742:Gasoline / Q000032:analysis*; D016018:Least-Squares Analysis
chemical_list: D056804:Biofuels; D005742:Gasoline