Abstract: A mass spectrometer interface, having improved sensitivity and reduced chemical background, is disclosed. The mass spectrometer interface provides improved desolvation, chemical selectivity and ion transport. A flow of partially solvated ions is transported along a tortuous path into a region of disturbance of flow, where ions and neutral molecules collide and mix. Thermal energy is applied to the region of disturbance to promote liberation of at least some of the ionized particles from any attached impurities, thereby increasing the concentration of the ionized particles having the characteristic m/z ratios in the flow. Molecular reactions and low pressure ionization methods can also be performed for selective removal or enhancement of particular ions.

Abstract: A mass analyzer includes a desolvation chamber into which an upstream gas is injected to provide a counter-flow to said downstream flow in the chamber. The counter-flow may slow the downstream flow of solvated ionized particles in the chamber, while allowing lighter desolvated ions to travel toward an outlet aperture of the desolvation chamber.

Abstract: A mass spectrometer interface, having improved sensitivity and reduced chemical background, is disclosed. The mass spectrometer interface provides improved desolvation, chemical selectivity and ion transport. A flow of partially solvated ions is transported along a tortuous path into a region of disturbance of flow, where ions and neutral molecules collide and mix. Thermal energy is applied to the region of disturbance to promote liberation of at least some of the ionized particles from any attached impurities, thereby increasing the concentration of the ionized particles having the characteristic m/z ratios in the flow. Molecular reactions and low pressure ionization methods can also be performed for selective removal or enhancement of particular ions.

Abstract: A mass spectrometer interface, having improved sensitivity and reduced chemical background, is disclosed. The mass spectrometer interface provides improved desolvation, chemical selectivity and ion transport. A flow of partially solvated ions is transported along a tortuous path into a region of disturbance of flow, where ions and neutral molecules collide and mix. Thermal energy is applied to the region of disturbance to promote liberation of at least some of the ionized particles from any attached impurities, thereby increasing the concentration of the ionized particles having the characteristic m/z ratios in the flow. Molecular reactions and low pressure ionization methods can also be performed for selective removal or enhancement of particular ions.

Abstract: An ion source and method for providing ionized particles to a molecular/atomic analyser, such as a mass spectrometer, are disclosed. The ion source includes a vessel defining a channel; a gas inlet extending from the gas source into the channel, for introducing a gas flow into the channel; a sample inlet extending into the channel for introducing sample within the channel; and an ionizer to ionize the sample in the channel. The vessel is sufficiently sealed to allow the channel to be pressurized, at a pressure in excess of 100 Torr. At least one gas source maintains the pressure of the channel at a pressure in excess of 100 Torr and the pressure exterior to the channel at a pressure in excess of 0.1 Torr and provides a gas flow that sweeps across the ionizer to guide and entrain ions from the ionizer to the outlet.

Abstract: An ion guide includes a plurality of rods, arranged about an axis that extends lengthwise from one end to the other of the guide. The rods guide ions in a guide region along and about the axis. A conductive casing surrounds the rods. The casing and the rods are geometrically arranged to produce an axial electric field along the axis. Specifically, the geometry is such that a first constant applied DC voltage (UDC), applied to the rods, and a second constant applied DC voltage (UCASE) applied to the casing, produce a voltage gradient between said casing and said axis that has a different magnitude at different positions along said axis.

Abstract: An ion detector includes collision surfaces for converting both positively and negatively charged ions into emitted secondary electrons. Secondary electrons may be detected using an electron detector, than may, for example include an electron multiplier. Conveniently, secondary electrons (or electrons emitted by the multiplier) may be detected using an electron pulse counter.

Abstract: An ion source and method for providing ionized particles to a molecular/atomic analyser, such as a mass spectrometer, are disclosed. The ion source includes a vessel defining a channel; a gas inlet extending from the gas source into the channel, for introducing a gas flow into the channel; a sample inlet extending into the channel for introducing sample within the channel; and an ionizer to ionize the sample in the channel. The vessel is sufficiently sealed to allow the channel to be pressurized, at a pressure in excess of 100 Torr. At least one gas source maintains the pressure of the channel at a pressure in excess of 100 Torr and the pressure exterior to the channel at a pressure in excess of 0.1 Torr and provides a gas flow that sweeps across the ionizer to guide and entrain ions from the ionizer to the outlet.

Abstract: An ion guide includes multiple stages. An electric field within each stage guides ions along a guide axis. Within each stage, amplitude and frequency, and resolving potential of the electric field may be independently varied. The geometry of the rods maintains a similarly shaped field from stage to stage, allowing efficient guidance of the ions along the axis. In particular, each rod segment of the ith of stage has a cross sectional radius ri, and a central axis located a distance Ri+ri from the guide axis. The ratio ri/Ri and is substantially constant along the guide axis, thereby preserving the shape of the field.

Abstract: A mass spectrometer interface, having improved sensitivity and reduced chemical background, is disclosed. The mass spectrometer interface provides improved desolvation, chemical selectivity and ion transport. A flow of partially solvated ions is transported along a tortuous path into a region of disturbance of flow, where ions and neutral molecules collide and mix. Thermal energy is applied to the region of disturbance to promote liberation of at least some of the ionized particles from any attached impurities, thereby increasing the concentration of the ionized particles having the characteristic m/z ratios in the flow. Molecular reactions and low pressure ionization methods can also be performed for selective removal or enhancement of particular ions.