Abstract: Method and apparatus for analyzing organic material present in a surface region (5) of a sample (1), the apparatus comprising: an evacuable sample receiving chamber (2); means (3) for generating an energetic beam (4) of particles or photons and for directing the beam onto the sample whereby to cause the removal therefrom of at least some organic material into a spatial region (7) proximate to the surface region; means (13) for generating non-coherent ultra-violet radiation (14); and means (13) for directing that radiation into the spatial region to photoionize organic material therein; means (35) for mass analyzing resultant ionized species; and means for conducting ions from the spatial region to the means for mass analyzing.