a fraction obtained from a liquid chromatograph column is introduced into a cup - shaped collecting vessel 12 having a centrally apertured funnel - shaped bottom surface 14 . a sample holder 13 is removably accommodated in the aperture , and after the evaporation of the fraction solvent the remaining residue 11 collects on or in the holder , which may then be removed and directly introduced into the ionization chamber of a mass spectrometer for further analysis .