Abstract: Systems and multiplexing methods for measuring the mass of multiple large molecules simultaneously using multiple ion trapping with charge detection mass spectrometry (CDMS) are described. The methods trap ions with a broad range of energies that decouple ion frequency and m/z measurements allowing energy measurements of each ion throughout the acquisition. The ion energy may be obtained from the ratio of the intensity of the fundamental to the second harmonic frequencies of the periodic trapping oscillation making it possible to measure both the m/z and charge of each ion. Because ions with the exact same m/z but different energies appear at different frequencies, the probability of ion-ion interference is significantly reduced. By maximizing the decoupling of ion m/z from frequency, the rate of signal overlap is significantly reduced making it possible to trap more ions and substantially reduce analysis time.

Abstract: An instrument for energizing molecules contained in a sample solution may include a droplet generator configured to generate droplets of the sample solution. The droplet generator illustratively has an elongated nozzle defining an orifice at one end thereof from which the droplets exit the droplet generator, and the orifice illustratively defines a first longitudinal axis centrally therethrough. A molecule energizing source is configured to produce a molecule energizing field, and is positioned relative to the nozzle orifice such that the molecule energizing field extends into at least some of the generated droplets along a direction non-parallel with the first longitudinal axis. The molecule energizing field illustratively carries energy which heats at least one of the generated droplets sufficiently to induce structural changes in at least one molecule contained in the at least one of the generated droplets.

Abstract: Systems and multiplexing methods for measuring the mass of multiple large molecules simultaneously using multiple ion trapping with charge detection mass spectrometry (CDMS) are described. The methods trap ions with a broad range of energies that decouple ion frequency and m/z measurements allowing energy measurements of each ion throughout the acquisition. The ion energy may be obtained from the ratio of the intensity of the fundamental to the second harmonic frequencies of the periodic trapping oscillation making it possible to measure both the m/z and charge of each ion. Because ions with the exact same m/z but different energies appear at different frequencies, the probability of ion-ion interference is significantly reduced. By maximizing the decoupling of ion m/z from frequency, the rate of signal overlap is significantly reduced making it possible to trap more ions and substantially reduce analysis time.

Abstract: An instrument for energizing molecules contained in a sample solution may include a droplet generator configured to generate droplets of the sample solution. The droplet generator illustratively has an elongated nozzle defining an orifice at one end thereof from which the droplets exit the droplet generator, and the orifice illustratively defines a first longitudinal axis centrally therethrough. A molecule energizing source is configured to produce a molecule energizing field, and is positioned relative to the nozzle orifice such that the molecule energizing field extends into at least some of the generated droplets along a direction non-parallel with the first longitudinal axis. The molecule energizing field illustratively carries energy which heats at least one of the generated droplets sufficiently to induce structural changes in at least one molecule contained in the at least one of the generated droplets.

Abstract: A new experimental setup for spatially resolved ambient infrared laser ablation mass spectrometry (AIRLAB-MS) that uses an infrared microscope with an infinity-corrected reflective objective and a continuous flow solvent probe coupled to a Fourier transform ion cyclotron resonance mass spectrometer is described. The efficiency of material transfer from the sample to the electrospray ionization emitter was determined using glycerol/methanol droplets containing 1 mM nicotine and is ˜50%. This transfer efficiency is significantly higher than values reported for similar techniques.

Abstract: A new experimental setup for spatially resolved ambient infrared laser ablation mass spectrometry (AIRLAB-MS) that uses an infrared microscope with an infinity-corrected reflective objective and a continuous flow solvent probe coupled to a Fourier transform ion cyclotron resonance mass spectrometer is described. The efficiency of material transfer from the sample to the electrospray ionization emitter was determined using glycerol/methanol droplets containing 1 mM nicotine and is ˜50%. This transfer efficiency is significantly higher than values reported for similar techniques.

Abstract: A method and apparatus for continuously introducing samples for mass spectrometry analysis which comprises providing sample molecules in an aqueous solution containing one or more organic solvents, preferably ethylene glycol, introducing said aqueous solution into the vacuum chamber of an ion source to enable said solution to solidify into a thread of solid matrix, and exposing the solid matrix to a source of energy to desorb sample molecules to be analyzed. The desorbed molecules are then photoionized and focused into a mass spectral analysis zone. The technique is suitable for interfacing liquid chromatographic separation techniques.

Abstract: Surface induce dissociation (SID) in a reflectron tandem time-of-flight mass spectrometer is demonstrated using a movable "in-line" SID surface in the reflectron lens. For collisions under 100 eV, SID spectra are measured with a resolution of .about.65 (FWHM) with dissociation efficiencies of 7-15% obtained for most small organic ions. For larger peptide ions (m/z>1200) formed by laser desorption, efficiencies as high as 30-50% are obtained. Surface collisions of polycyclic aromatic hydrocarbon ions can be made to produce abundant pick-up of large, surface-adsorbed species. Attachment of C.sub.1 H.sub.n -C.sub.6 H.sub.n to naphthalene and phenanthrene ions occurs with collision energies between 40-160 eV. Formation efficiency for these ion-adsorbate attachment reactions can be as high as 0.8%. Surface collisions produce no measureable shift in our flight times nor distortion in peak shapes for these species; this indicates the reaction time on the surface must be less thant 160 ns.

Abstract: The simultaneous collection of multiple spectra using tandem and multidimensional mass spectrometry from multiple precursors yields correspondingly enhanced sensitivity through Hadamard transform deconvolution. For MS.sup.n spectra, the product relationships are coded by a Hadamard differences method wherein the combined daughter spectrum of a selected half of the precursors is subtracted from the combined daughter spectrum of the remaining precursors, so that no ions are lost.