Abstract: An ion trap for a mass spectrometer has a conductive central electrode with an aperture extending from a first open end to a second open end. A conductive first electrode end cap is disposed proximate to the first open end thereby forming a first intrinsic capacitance between the first end cap and the central electrode. A conductive second electrode end cap is disposed proximate to the second open end thereby forming a second intrinsic capacitance between the second end cap and the central electrode. A first circuit couples the second end cap to a reference potential. A signal source generating an AC trap signal is coupled to the central electrode. An excitation signal is impressed on the second end cap in response to a voltage division of the trap signal by the first intrinsic capacitance and the first circuit.

Abstract: A chemical analysis system is disclosed wherein, in evacuating a preconcentrator housing (2) prior to desorption, a pump system (13) reduces an internal pressure of the preconcentrator housing to a level substantially equal to an internal pressure of a chemical analyzer such that flow restrictors and/or membranes (15) between the chemical analyzer (7) and the preconcentrator housing (2) may be omitted. The chemical analysis system includes a chemical analyzer (7), a preconcentrator housing (2) coupled to the chemical analyzer, the preconcentrator housing enclosing a temperature control element (5, 18) and a sorbent material (1), the temperature control element configured to heat the sorbent material to adsorb or desorb a chemical of interest; and a pump system (13) coupled to the preconcentrator housing and the chemical analyzer, the pump system configured to evacuate the preconcentrator housing prior to desorption of the chemical of interest.

Abstract: A chemical pre-concentrator includes a conduit defining a flow path between two ends and having a heating element disposed within the conduit, such that the heating element has at least one sorbent material deposited directly on at least a portion of a conductive surface of the heating element. Some such heating elements are in the form of electrically conductive strips defining both a plurality of apertures through the strip and a series of undulations spaced along the flow path.

Abstract: In one general aspect, a sample is transferred into a mass spectrometer by capturing a sample on a collector, inserting the collector into a sample chamber coupled to the mass spectrometer and a vacuum pump, evacuating the sample chamber using the vacuum pump to reduce an internal pressure of the sample chamber to a level less than atmospheric pressure, heating the collector to release the sample from the collector, and introducing the sample into the mass spectrometer from the evacuated sample chamber.

Abstract: A radio frequency (RF) drive system and method for driving the ion trap or mass filter of a mass spectrometer has a programmable RF frequency source coupled to a RF gain stage. The RF gain stage is transformer coupled to a tank circuit formed with the ion trap or mass filter. The power of the RF gain stage driving the ion trap or mass filter is measured using a sensing circuit and a power circuit. A feedback value is generated by the power circuit that is used to adjust the RF frequency source. The frequency of the RF frequency source is adjusted until the power of the RF gain stage is at a minimum level. The frequency value setting the minimum power is used to operate the RF drive system at the resonance frequency of the tank circuit formed with the transformer secondary inductance and the ion trap or mass filter capacitance.

Abstract: A radio frequency (RF) drive system and method for driving the ion trap or mass filter of a mass spectrometer has a programmable RF frequency source coupled to a RF gain stage. The RF gain stage is transformer coupled to a tank circuit formed with the ion trap or mass filter. The power of the RF gain stage driving the ion trap or mass filter is measured using a sensing circuit and a power circuit. A feedback value is generated by the power circuit that is used to adjust the RF frequency source. The frequency of the RF frequency source is adjusted until the power of the RF gain stage is at a minimum level. The frequency value setting the minimum power is used to operate the RF drive system at the resonance frequency of the tank circuit formed with the transformer secondary inductance and the ion trap or mass filter capacitance.

Abstract: An ion trap for a mass spectrometer has a conductive central electrode with an aperture extending from a first open end to a second open end. A conductive first electrode end cap is disposed proximate to the first open end thereby forming a first intrinsic capacitance between the first end cap and the central electrode. A conductive second electrode end cap is disposed proximate to the second open end thereby forming a second intrinsic capacitance between the second end cap and the central electrode. A first circuit couples the second end cap to a reference potential. A signal source generating an AC trap signal is coupled to the central electrode. An excitation signal is impressed on the second end cap in response to a voltage division of the trap signal by the first intrinsic capacitance and the first circuit.