Abstract: An apparatus for use in atmospheric pressure ionization includes a sample receiving chamber, a sample droplet source communicating with the sample receiving chamber, an outlet conduit, and a boundary. The outlet conduit defines a sampling orifice that communicates with the sample receiving chamber. The boundary is interposed between the sample receiving chamber and the sampling orifice and comprises an opening. The opening defines a first passage through which a drying gas is flowable into the sample receiving chamber in an elongated flow profile, and a second passage through which sample material is flowable from the sample receiving chamber toward the sampling orifice. The first passage is positioned in non-coaxial relation to the second passage. The first passage is configured to introduce the elongated flow profile of the drying gas into a pathway of droplets of the sample material flowing toward the second passage.

Abstract: A self-aligned ion guide assembly comprises a plurality of 2N rods radially contained by at least one insulating collar having two grooves axially displaced on the outer periphery of the collar. A wire in each groove electrically contacts and mechanically bonds to alternate rods through respective radially directed holes. Alternatively, the collar is cast about the assembly of rods and wires.

Abstract: A self-aligned ion guide assembly comprises a plurality of 2N rods radially contained by at least one insulating collar having two grooves axially displaced on the outer periphery of the collar. A wire in each groove electrically contacts and mechanically bonds to alternate rods through respective radially directed holes. Alternatively, the collar is cast about the assembly of rods and wires.

Abstract: An apparatus for electrospray ionization of a liquid sample matrix to prepare the sample for introduction into a mass spectrometer. The inventive electrospray interface is arranged between a source of a liquid sample matrix and an electrospray ionization needle. The interface includes a central chamber which contains elements for passively mixing the liquid sample flow with a modifying liquid added to the central chamber through a side channel. The side channel is isolated from the central chamber by a flow restrictor and the modifying liquid is provided to the side channel through a valve. A second valve, side channel, and flow restrictor are used to permit introduction of a calibration fluid into the central chamber through the first side channel. The inventive interface permits mixing of a modifying liquid with the liquid sample matrix to assist in nebulization of the liquid sample by reducing the surface tension of the sample containing fluid.

Abstract: An apparatus for producing gas-phase ions from a sample compound in a carrier liquid. The electrospray needle (or capillary) of the present invention includes a central metal tube which carries the liquid containing the sample compound. The central tube is surrounded by a plurality of tubes which transport a nebulizing gas. The nebulizing gas tubes are placed symmetrically around the outside of the liquid containing tube. The nebulizer of the present invention produces a symmetric, non-annular gas flow which has variations in pressure around the circumference of the central tube. The pressure variations of the nebulizing gas flow produce additional shear forces on the liquid emerging from the central tube. This assists in forming a uniform electrospray of droplets from the liquid at lower nebulizing gas flow rates, thereby reducing the disadvantageous effects of the higher gas flow rates used in the art.

Abstract: An apparatus for efficiently removing a carrier liquid from charged liquid drops formed by electrospray ionization prior to introduction of the drops into a mass spectrometer. A central capillary tube connects a region of the low pressure vacuum system containing the mass spectrometer with a region at substantially atmospheric pressure, in which ion formation is produced by electrospray ionization. Heated, drying gas flows through a plurality of vortex forming channels symmetrically disposed about the axis of the central capillary tube which provides an entrance to the spectrometer. Gas exiting the vortex forming channels enters tangentially to the inside of a vortex drying tube with a small helix angle, causing the gas to swirl around the tube, forming a vortex. The vortex drying gas flows in a direction that is substantially transverse to the axis of the entrance capillary into the mass spectrometer.

Abstract: A chromatography oven is described to achieve faster cool-down rates and to preferably lower the temperature difference that can be maintained between the oven temperature and ambient temperature. The oven includes a suitable housing having front and rear walls and four side walls, a fan within the housing adjacent to the rear walls, an ambient air intake vent means in the rear wall, and an exhaust vent means within a rear corner of one of the side walls adjacent to the rear wall for exhausting the tangential flow of air created by the rotating fan.