A series of chromatograms were run to illustrate the advantages of
using butanol as an organic modifier for the separation of vanillin,
derivatives of vanillin and coumarin. The test mixture consisted of
six compounds (see Fig. 1). Fig. 2A shows a chromatogram of the
vanillin test mixture using the methanol–water mobile phase (25%
methanol in water with 0.2% acetic acid) that yielded the best separation
on the BDS C18 column at ambient temperature. Fig. 2B
shows a chromatogram of the same test mixture on a butanol water