Abstract: Sample material ionized in a sample receiving chamber is flowed into a sample conduit. Drying gas may also flow into the sample conduit and may be heated. The pressure and length of the sample conduit may be provided according to the product 50 or greater Torr?cm. The sample conduit may include a turn. The sample conduit may lead to an ion extraction chamber at which a sampling orifice may lead to a mass spectrometer. The diameter of the sample conduit may be larger than the diameter of the sampling orifice. An electrical field may be applied in the ion extraction chamber to slow incoming ions. A voltage jump may be applied to the sample conduit.

Abstract: The NMR device with a magnet utilizes a composition exhibiting a desired value of magnetic susceptibility, wherein the composition comprises a metal ion selected from the group consisting of Gd+3, Fe+3 and Mn+2 and an amorphous material using a ligand or chelating agent to solubilize the metal ion throughout the amorphous material, wherein the magnetic susceptibility of the composition exhibits a desired value at cryogenic temperatures such as nearly zero susceptibility at temperatures at or below 77 K.

Abstract: An elongate sample volume matching an elongate region of uniform RF magnetic field established by a saddle coil, is approximated by at least one pair of cylindrical sample tubes in parallel orientation with the geometric axis of the saddle coil. The displacement of the two cylindrical tubes defines a direction transverse to the tube axes and this transverse direction is aligned parallel with the RF magnetic field of the saddle coil.

Abstract: A method and apparatus are provided for optimizing a liquid chromatography/mass spectrometry system for gradient elution. A temperature profile is determined according to which a gas is flowed into an atmospheric pressure ionization interface for vaporizing a matrix flowed into the interface from a liquid chromatography column. A flow profile is determined according to which the gas is flowed into the interface for preventing entry of the matrix into the mass spectrometer when the matrix does not include an analyte for which detection is desired. The determination of the temperature and flow profiles is based on the characteristics of the matrix as it eludes from column into the interface. A heat control device and a flow control device can be provided for implementing the temperature profile and flow profile, respectively. The heating control device and flow control device can be programmed or controlled by software.

Abstract: A rotor drive apparatus includes a rotor and a stator. The stator has a gas injection orifice located on the axis about which the rotor spins. The gas injection orifice communicates with a bearing gap formed between a tapered surface of the rotor and an axially spaced tapered surface of the stator. A gas is flowed from the gas injection orifice through the bearing gap, thereby establishing a center-fed, radial-outflow gas bearing supporting the rotor during rotation. In one implementation, a separate flow of drive gas is fed to drive flutes of the rotor to drive rotation. In another implementation, the center-fed, radial-outflow gas flow is additionally utilized to impinge against the drive flutes to actuate the rotation.

Abstract: An electrode for use in a device such as an ion trap has an axial length extending generally in the direction of a central axis from a first axial end to a second axial end, and an inside surface. The inside surface includes a surface profile that is uniform from the first axial end to the second axial end, or at least is uniform for a uniform section length along the axial direction. The electrode may include an elongated surface feature such as a groove that extends for at least the uniform section length. An aperture may communicate with the groove. The electrode may be axially segmented into regions. Gaps between the regions may be oriented at an angle relative to a plane orthogonal to the central axis. The electrode may be one of several electrodes arranged as an electrode structure coaxially disposed about an elongated interior space.

Abstract: Trace gas leak detectors and methods for trace gas leak detection of large leaks at relatively high test pressures are provided. A trace gas leak detector includes a test port to receive a sample containing a trace gas, the test port connected to a test line, a mass spectrometer to detect the trace gas, a high vacuum pump having an inlet port coupled to the inlet of the mass spectrometer, and a forepump having a main inlet, at least one intermediate inlet and an exhaust. The main inlet of the forepump is coupled to the exhaust port of the high vacuum pump. The intermediate inlet is controllably connected to the test line. The forepump is selected from the group consisting of a scroll vacuum pump and a screw vacuum pump.

Abstract: A switchable birdcage coil functioning as a transmitter coil and a separate RF surface coil functioning as the receiver coil are utilize in NMR and MRI apparatus. To prevent the switchable birdcage coil from absorbing energy by coupling to the receiver coil or by absorbing power from the RF field produced by the precessing nuclear spins, one or more of the reactive elements of the birdcage coil are switched from a normal reactive impedance state to a high impedance state. The high impedance state is formed by switchably combining the reactive element with a complementary reactive element thereby forming parallel resonant high impedance circuit that is tuned to resonate at the NMR frequency.

Abstract: A leak detector includes a leak detector inlet to receive a test gas, a vacuum pump coupled to the leak detector inlet, a test gas sensing unit connected through a passage to the leak detector inlet, to sense the test gas, a membrane that is permeable to the test gas, the membrane disposed in the passage between the leak detector inlet and the test gas sensing unit, and a control mechanism to substantially terminate transmission of the test gas through the membrane in a time of 500 milliseconds or less. In other embodiments, the control mechanism substantially terminates transmission of the test gas through the membrane in a time of 100 milliseconds or less.

Abstract: An composition exhibiting a desired value of magnetic susceptibility, which can be used to fabricate components in an NMR device, and method thereof, wherein the composition comprises a metal ion selected from the group consisting of Gd+3, Fe+3 and Mn+2 and an amorphous material using a ligand or chelating agent to solubilize the metal ion throughout the marphous material, wherein the magnetic susceptibility of the composition exhibits a desired value at cryogenic temperatures such as nearly zero susceptibility at temperatures at or below 77° K.

Abstract: An electrode structure for manipulating ions includes a main electrode and a compensation electrode. An outer surface of the main electrode includes a curved section that includes an apex. An aperture is generally disposed at the apex and extends along a radial center line from the outer surface through a thickness of the main electrode. The compensation electrode is disposed at the radial center line and at a tangent line tangent to the apex. Another electrode structure includes a plurality of main electrodes defining an interior space, and one or more compensation electrodes disposed in the interior space. RF signals may be applied to the main electrodes and to the compensation electrode.

Abstract: Simultaneous sample purification, enrichment and analysis of pharmaceuticals, illicit drugs, pollutants, biotechnological products, synthetic organic reaction products and food/flavor ingredients from complex matrices can be performed using porous hollow fiber or porous-disk liquid-membrane devices. The devices are part of a multi-well (e.g. 96-well) plate. The devices can be used for selective separation and enrichment of complex mixtures containing trace levels of analytes, and can be used in tandem with analytical instruments which routinely handle multiple samples under high throughput screening conditions. A multi-well/multi-vial plate can into state-of-the-art HPLC or GC sampling systems or LC/MS or GC/MS instruments. Samples can be enriched several orders of magnitude and can directly be withdrawn from the fiber and injected into the chromatographic instruments. Alternatively, these enriched samples can be introduced directly into MS, CE or other detection devices.

Abstract: A split joint (31) for vacuum pumps, suitable for establishing the mechanical connection and vacuum seal between the suction inlet (25) of a vacuum pump (35) and an evacuation outlet (65) of a structure (39) to which the pump is to be connected; said split joint comprising a male joint (33; 37) equipped with a plurality of male engagement elements (41; 43) connectable to the outer case of a vacuum pump or to the structure to which the pump is to be connected; said male engagement elements providing the mechanical connection with corresponding female engagement elements (41; 43) of the corresponding female joint; wherein the mechanical connection is achieved by a relative rotating movement between said male joint (33; 37) and said female joint (37; 33).

Abstract: Mass spectrometers for trace gas leak detection and methods for operating mass spectrometers are provided. The mass spectrometer includes an ion source to ionize trace gases, such as helium, a magnet to deflect the ions and a detector to detect the deflected ions. The ion source includes an electron source, such a filament. The method includes operating the electron source at an electron accelerating potential relative to an ionization chamber sufficient to ionize the trace gas but insufficient to form undesired ions, such as triply charged carbon.

Abstract: The invention provides devices and methods for performing liquid phase microextraction of at least one analyte from an aqueous sample, wherein the device comprises a liquid membrane comprising a fatty acid ester, a vegetable oil, a silicone oil, a nitroarylalkylether, or mixtures thereof, and an optional carrier, supported on a porous polymeric substrate. In a preferred embodiment, the porous polymeric substrate is a hollow fiber. The devices and methods for preparing them provide stable liquid membranes for performing liquid phase microextraction, where the membranes can be stored for 30, 60 or 90 days prior to use.

Abstract: According to one aspect, a nuclear magnetic resonance (NMR) radio-frequency (RF) coil of an NMR spectrometer includes oppositely-facing arches at opposite longitudinal ends of the coil window, along shielded regions of the coil. The arched coil shapes allow situating the transverse parts of the coil away from the interfaces between the sample measurement volume and coil shields while minimizing the additional coil length and thus coil inductance and capacitance needed to move the transverse conductors away from interfaces. Moving the transverse parts of the coil away from the measurement volume facilitates shimming. The coil may be lifted on a plurality of longitudinal support rods spaced around a circumference of the coil, in order to reduce the capacitance between the coil and associated shields.

Abstract: An NMR probe includes a coil former on which the resonant capacitance and/or tune and match capacitances are integrally implemented. Adjustable capacitances are realized in combination with a composite former including a slip glass for support of a capacitor plate. Particular advantages are realized in the context of cryostatic NMR probes.

Abstract: RF electric fields produced by electric potential differences in the NMR probe coil windings may penetrate the NMR sample and sample tube causing sensitivity loss and increased noise in NMR spectroscopy. Electrically conducting strips in close proximity to the windings of the NMR probe coil and oriented at right angles to direction of the coil winding they cross provide an alternative path for these electric fields while causing negligible effect upon the RF magnetic field, thereby increasing the sensitivity of the NMR probe.

Abstract: A hybrid turbomolecular vacuum pump includes a housing having an inlet port and an exhaust port, one or more axial flow stages located within the housing, each of the axial flow stages including a stator and an impeller, each having inclined blades, at least one additional vacuum pumping stage which is not an axial flow stage, the additional vacuum pumping stage being located within the housing and including a stator and an impeller, and a motor to rotate the impellers such that gas is pumped from the inlet port to the exhaust port. The vacuum pump does not include a molecular drag stage having a rotating cylindrical drum or a rotating disk with a flat pumping surface. The additional vacuum pumping stage may be a modified molecular drag stage, wherein the impeller includes a disk having a roughened or grooved pumping surface, and/or a regenerative stage.

Abstract: Ultraporous sol gel monoliths and methods for preparing the same are provided, having superior flow characteristics for chromatography and analytical chemistry applications. The methods for forming an ultra porous sol-gel monolith include (a) forming a solution comprising a porogen, a matrix dissolving catalyst and a sol gel precursor; (b) allowing the solution to form a gel; and (c) drying the gel at an elevated temperature. The ultraporous sol gel monoliths are characterized by a porosity of up to about 97%, a BET surface area of at least about 50 m2/g and substantially no micropores.