Abstract: Among other things, methods, systems, apparatus for performing on-the-fly apportionment are described. In particular, a mass spectrometry apparatus includes an ionization laser to produce a deionization laser beam. The apparatus also includes a particle beam path that receives aerosol particles and intersects the ionization laser beam at a location where aerosol particles are desorbed and ionized by the laser beam. The apparatus also includes an ion extractor located at or near the ionization location to separate positive ions and negative ions desorbed from the aerosol particles and to direct the positive ions along a first direction of an ion path and the negative ions along a second, opposite direction of the ion path. The apparatus also includes a first reflectron located at a first side of the ion extractor, on the ion path, to reflect the positive ions along a first reflection path that deviates from the ion path.

Abstract: Among other things, methods, systems, apparatus for performing on-the-fly apportionment are described. In particular, spectrum data associated with a particle is acquired in real-time. The acquired real-time spectrum data is analyzing in real-time to classify the particle. Analyzing the data in real-time includes comparing the acquired spectrum data with a library of known mass spectral fingerprints to obtain a match.

Abstract: Among other things, methods, systems, apparatus for performing on-the-fly apportionment are described. In particular, a mass spectrometry apparatus includes an ionization laser to produce a deionization laser beam. The apparatus also includes a particle beam path that receives aerosol particles and intersects the ionization laser beam at a location where aerosol particles are desorbed and ionized by the laser beam. The apparatus also includes an ion extractor located at or near the ionization location to separate positive ions and negative ions desorbed from the aerosol particles and to direct the positive ions along a first direction of an ion path and the negative ions along a second, opposite direction of the ion path. The apparatus also includes a first reflectron located at a first side of the ion extractor, on the ion path, to reflect the positive ions along a first reflection path that deviates from the ion path.

Abstract: Among other things, methods, systems, apparatus for performing on-the-fly apportionment are described. In particular, spectrum data associated with a particle is acquired in real-time. The acquired real-time spectrum data is analyzing in real-time to classify the particle. Analyzing the data in real-time includes comparing the acquired spectrum data with a library of known mass spectral fingerprints to obtain a match.

Abstract: An ion mobility/mass spectrometry method and instrument using aerosolized samples and dual positive and negative mode detection is described. Sample preparation methods are also described.

Abstract: An ion mobility/mass spectrometry method and instrument using aerosolized samples and dual positive and negative mode detection is described. Sample preparation methods are also described.

Abstract: A portable analyzer for determining the size and chemical composition of particles suspended in an aerosol. The aerosol is accelerated through a nozzle and skimmers, to produce a well-defined beam of particles, the speed of which is inversely related to the particle size. A dual-beam laser system positioned along the beam path detects light scattered from each particle, to determine the particle's velocity and thus its aerodynamic size. The laser system also triggers a laser to produce a beam that irradiates the particle, to desorb it into its constituent molecules. The particle is desorbed in a source region of a bipolar, time-of-flight mass spectrometer, which provides a mass-to-charge spectrum of the desorbed molecule, thereby chemically characterizing the material of the particle. Several structural features provide sufficient ruggedness to allow the analyzer to be easily used in the field with minimum calibration and maintenance.

Abstract: The invention provides an improved mass spectrometer apparatus, and related method, that characterizes aerosol particles, in real time, according not only to their chemical composition, but also to their size. This added information can be of critical importance when evaluating risks associated with aerosol particles of particular chemical composition. The apparatus achieves this beneficial result in a reliable fashion by first detecting the presence and size of individual aerosol particles moving along a predetermined particle path and by then directing a pulse of high-intensity light at the particle, to desorb and ionize the particle, for analysis of its chemical composition.