We have applied the technique of EELS (=electron energy loss spectroscopy) to the liquid surface of 3-hydroxypropionitrile. Even though the presence of the vapor deteriorates the performance of the spectrometer, the resolution is sufficient to separate the vibrational stretch modes of the three groups OH, CH, CN. The energy dependence allows to identify non-resonant and resonant excitation mechanisms. Comparison to gas phase results, measured in the same apparatus, leads to a surprising difference in the excitation of the CN group. The different environment in the liquid and gaseous phase appears to strongly influence the character of the electronic resonance state.