A new atmospheric pressure (AP) infrared (IR) matrix-assisted laser desorption/ionization (MALDI) ion source was developed and interfaced with a Thermo Finnigan LCQ ion trap mass spectrometer. The source utilized a miniature all-solid-state optical parametric oscillator (OPO)-based IR laser system tunable in the ϭ 1.5-4 m spectral range and a nitrogen ultraviolet (UV) laser ( ϭ 337 nm) for use in comparative studies. The system demonstrated comparable performance at 3 m and 337 nm wavelengths if UV matrices were used. However, AP IR-MALDI using a 3 m wavelength showed good performance with a much broader choice of matrices including glycerol and liquid water. AP IR-MALDI mass spectra of peptides in the mass range up to 2000 Da were obtained directly from aqueous solutions at atmospheric conditions for the first time. A potential use of the new AP IR-MALDI ion source includes direct MS analysis of biological cells and tissues in a normal atmospheric environment as well as on-line coupling of mass spectrometers with liquid separation techniques. (J Am Soc Mass Spectrom 2002, 13, 354 -361)

An atmospheric pressure (AP) infrared (IR) laser ionization technique, implemented on a quadrupole ion trap mass spectrometer, was used to analyze underivatized, N-linked oligosaccharides in solution. Experiments were conducted on an atmospheric pressure infrared ionization from solution (AP-IRIS) ion source which differed from previous AP IR matrix-assisted laser desorption/ionization (MALDI) interfaces in that the ion source operated in the absence of an extraction electric field with a higher power 2.94 microm IR laser. The general term 'IRIS' is used as the mechanism of ionization differs from that of MALDI, and is yet to be fully elucidated. The AP-IRIS ion source demonstrated femtomole-level sensitivity for branched oligosaccharides. AP-IRIS showed approximately 16 times improved sensitivity for oligomannose-6 and the core-fucosylated glycan M3N2F over optimal results obtainable on a AP UV-MALDI with a 2,4,6-trihydroxyacetophenone matrix. Comparison between IR and UV cases also showed less fragmentation in the IR spectrum for a glycan with a conserved trimannosyl core, core-substituted with fucose. A mixture of complex, high-mannose and sialylated glycans resulted in positive ion mass spectra with molecular ion peaks for each sugar. Tandem mass spectrometry of the sodiated molecular ions in a mixture of glycans revealed primarily glycosidic (B, Y) cleavages. The reported results show the practical utility of AP-IRIS while the ionization mechanism is still under investigation.

A home-built multifunctional computerized spectrometer for optical detection of magnetic resonance (ODMR) is described. Preliminary results of studying Yb 3 + ions in BaF, single crystal by electron paramagnetic resonance, ODMR and optical spectroscopy are presented.

Electron and ion optical design software for integrated circuit manufacturing equipmentWe made a multiple electron microcolumn array. The electron source was made of either a Si based field emission array or a nickel coated array to keep the distances among sources equal. Laser micromachining was used to obtain a self-aligned microcolumn with five lenses: an extractor, an accelerator, and an Einzel lens. The aberration of each column was greatly improved compared to anodically bonded Si lens microcolumns. The field emission electron beam pattern was obtained from a multiple microcolumn. Its I -V dependence and possible application to the electron beam lithography with high throughput is discussed.

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