“…Chemometric tools to classify or analyze biodiesels for chemical information have included principal component analysis (PCA) [17,18], PCA-projections to latent structures [14], partial least squares (PLS) [19,20], PLS combined with PCA, hierarchical cluster analysis (HCA), Knearest neighbor (KNN) [21], and support vector machines (SVM) with PLS/ multivariate adaptive regression splines (MARS) [22]. Other applications of chemometric methods include quantitative determinations of blends with biodiesel, petrodiesel, and a renewable hydrocarbon by NIR spectrometry [4,23], the percent composition in biodiesel/petrodiesel by GC×GC-TOFMS [11], evaluation of blend quality by proton NMR [24], classification of blends by FT-ICR 6 MS [22], and the determination of methyl esters in biodiesel blends using FTIR-ATR and FTNIR [25]. Chemometric tools have been applied successfully with complex data sets from GC-DMS analyses although matrix interferences were not considered significant complications [15].…”