PHOTOIONIZATION MASS-SPECTROMETER WITH A MICROSCOPE LASER DESORPTION SOURCE

An apparatus is been described in which laser desorption, separate laser ionization, mass spectrometry, and microscopy are combined. An UV waveguide laser is focused on a sample, which is mounted on translation stages in vacuum. Desorbed neutral molecules are ionized above the surface by a second laser, and ions are extracted into a reflectron time of flight mass spectrometer. A spatial resolution of 1-mu-m is demonstrated, with a mass resolution of 2000 and a detection efficiency of 10(-4).