A method for element analysis is proposed which is based on measurements of energy changes in fast neutron scattering. Liquid scintillators (NE213 and NE230) are considered as neutron spectrometers for these energy measurements. Lineshapes of NE213 and NE230 detectors for monoenergetic 7.5 MeV neutrons have been determined and the response functions of the NE230 detector to neutrons scattered at 150 degrees from samples containing the elements C, N, O, Si, Al, and Fe have been measured. A method for estimating C:N:O atomic ratios from scattering measurements on compounds containing these elements is described and discussed.