ANALYTICAL CHARACTERISTICS AND APPLICATIONS OF LASER IONIZATION MASS-SPECTROMETRY

We have built a laser ionization mass spectrometer (LIMS) for chemical composition analysis of solid samples, which employs an Nd:YAG laser and a time-of-flight mass analyzer. in this spectrometer, the maximum mass we identified clearly is higher than 2000 amu. A mass resolution of 230 has been achieved at m/z 208 (Pb element) in the linear TOFMS a nd can be even improved up to 1550 by employing a reflectron. The dete ction limit is determined to be on the order of ppm for Fe and In. The depth resolution is found to be about 20 Angstrom/spectrum with a las er power of 0.5 J/cm(2). We also report a preliminary application of t he LIMS to identifying impurities resident in several solid samples.