1D continuous distribution of exponentials of biodiesel mixture samples. Relaxation time distributions are shown for biodiesel and (A) oil (BIO-OIL), (B) glycerol (BIO-GLY), (C) water (BIO-H2O) and (D) methanol (BIO-MeOH) mixtures. Relaxation time distributions were calculated using the WinDXP ILT software package. The relaxation time distributions of the pure materials are shown for reference. The position of the different peaks in (A)-(C) is constant also for composite samples, though the peaks in the BIO-OIL mixture are difficult to resolve because of overlapping of components and widening of peaks imposed partly by the WinDXP ILT algorithm. In (D) the position of the biodiesel peak is shifted toward the methanol probably because of solubility interactions between these two components.