Comparative performance of tripole and quadrupole ion guides at elevated pressure.

This study presents the first practical demonstration of an operational tripole ion guide. The transmission was measured for both the tripole and quadrupole ion guides at 1 Torr pressure. It was found that the quadrupole provides 2.

Atmospheric pressure ionization permanent magnet fourier transform ion cyclotron resonance mass spectrometry.

A new Fourier transform ion cyclotron resonance mass spectrometer based on a permanent magnet with an atmospheric pressure ionization source was designed and constructed. A mass resolving power (full-width-at-half-maximum) of up to 80,000 in the electron ionization mode and 25,000 in the electrospray mode was obtained. Also, a mass measurement accuracy at low-ppm level has been demonstrated for peptide mixtures in a mass range of up to 1200 m/z in the isotopically resolved mass spectra.

Coaxial multi-electrode cell ('O-trap') for high-sensitivity detection at a multiple frequency in Fourier transform ion cyclotron resonance mass spectrometry: main design and modeling results.

Separation of the functions of ion excitation and detection between different cell compartments allows for implementation of excitation and detection techniques unattainable in a single compartment of the conventional ion cyclotron resonance (ICR) cell. In particular, multi-electrode detection at a multiple of the main cyclotron frequency can be utilized without the loss of sensitivity and other negative effects. The new O-trap designed exclusively for ion detection adds an additional, internal coaxial cylinder around which ions with excited cyclotron orbits rotate.

Dissociation of peptide ions by fast atom bombardment in a quadrupole ion trap.

A new technique for fragmentation of cations and anions of peptides stored in ion traps including radiofrequency devices is described. The technique involves irradiation of peptide ions by a beam of particles generated by a fast atom bombardment (FAB) gun. This irradiation leads to fragmentation of N--C(alpha) backbone bonds (c- and z-fragments) and S--S bonds for cations and C(alpha)-C backbone bonds (a- and x-fragments) for anions of peptides.

High-throughput mass spectrometer using atmospheric pressure ionization and a cylindrical ion trap array.

The analytical performance of an atmospheric pressure sampling, multiple-channel, high-throughput mass spectrometer was investigated using samples of a variety of types. The instrument, based on an array of cylindrical ion traps, was built with four independent channels and here is operated using two fully multiplexed channels (sources, ion optics, ion traps, detectors) capable of analyzing different samples simultaneously. Both channels of the instrument were incorporated within the same vacuum system and operated using a common set of control electronics.