Radiant energy – Ionic separation or analysis – With sample supply means
Reexamination Certificate
2003-01-17
2004-04-20
Lee, John R. (Department: 2881)
Radiant energy
Ionic separation or analysis
With sample supply means
C250S281000, C250S282000
Reexamination Certificate
active
06723984
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to sampling systems for mass spectrometers and, more specifically, to an environmental sampler for a mass spectrometer that allows for controlled introduction of small amounts of fluids or gases into the vacuum system of the mass spectrometer under severe environmental conditions.
BACKGROUND OF INVENTION
There have been diverse types of samplers proposed for mass spectrometers. For example, U.S. Pat. No. 4,201,913 to Bursack et al. discloses an apparatus for introducing a gaseous sample into a mass spectrometer which includes a hollow antechamber or cavity disposed between the sample stream and a high vacuum enclosure. Orifice openings are provided in the antechamber which allow the antechamber to communicate both with the high vacuum enclosure and the sample stream. An electrically operated pulsed valve is used to admit a series of small volumes of sample by pulses of controlled duration and frequency such that the sample flow from the antechamber into the high vacuum enclosure can be made to resemble one of essentially constant flow.
U.S. Pat. No. 4,386,852 to Cassidy et al. discloses a phase synchronization apparatus useful for synchronizing the sample signal and the demodulation signal at a spectrometer, which included a stepper motor the position of which is controlled so that the desired phase synchronization is ensured.
U.S. Pat. No. 4,562,351 to Atherton et al. discloses a mass spectrometer having a sample insertion probe on which a reference compound and an unknown sample can be simultaneously introduced without mixing into a field ionization or ion or neutral particle bombardment ion source. An insulated support is mounted by a parallel hinge on the end of a probe shaft. Two or more separated segments or emitter wires, one carrying the unknown sample, and another carrying the reference compound, are mounted on a base member which is fitted to the support. A drive shaft, concentric with an outer probe shaft, has an eccentric peg on the end, which engages with a cam on the support, so that rotation of the drive shaft results in an oscillating motion of the segments or emitters, alternately positioning them in the optimum position for ionization. A spectrum of the sample or the reference compound can be obtained when required by selecting the appropriate position of the drive shaft. Rotation of the drive shaft may be controlled by a servo-mechanism and a computer. As a result, improved accuracy of mass measurement of peaks in the mass spectrum of the sample is achieved.
U.S. Pat. No. 4,590,165 to Gilles et al. disclosed an automatic sampling method for introducing a diluted viscous sample into an instrument for analysis for trace elements. The automatic sampling system includes a tube assembly, a member for mounting the tube assembly in proper relation, means for maintaining, between sampling, the free end of the tube assembly in a cleaning solution, and means for inserting the free end of the tube assembly into a sample contained within a container. Preferably, the instrument is a spectrometer, the samples are organic and aqueous samples, such as oils, brines, sludges, plating solutions and the like, and the trace elements include wear metals and also other elements, such as calcium, barium, zinc, sodium, magnesium, boron, phosphor and the like.
U.S. Pat. No. 4,601,211 to Whistler discloses a multi-port valve using a flexible sample tube to selectively intercept gases flowing from inlet ports into a common manifold space. The manifold space is placed under sufficient vacuum to ensure that gas samples will be selectively received by the sample tube when the sample tube is placed in close proximity to the selected inlet port to be sampled. The sample tube is arranged so that gases to be sampled from the selected port wash over the entrance end of the sample tube so that contaminated or mixed gases from the manifold space are prevented from entering the sample tube. The sample tube is mounted to pivot inside the valve body to selectively align the sample tube with the inlet ports. The valve body may be sealed by a cover through which the valve guide is driven to rotate by a magnetic coupling, or by a bearing seal through which the sample tube guide projects. The sample guide may be rotated in a stepwise fashion by a stepper motor for slow collection rates, or may be rotated quickly by a motor for rapid sampling. Magnetic detectors or a shaft decoder may be used to monitor the position of the sample tube guide. The multi-port valve may be used in a system in which a measuring device such as a mass spectrometer and a data system are used.
U.S. Pat. No. 4,879,458 to Brunfeldt discloses an automated sample inlet system for sequentially introducing a plurality of indium encapsulated samples into a mass spectrometer wherein the samples are placed in a micro tube and loaded into a circular carousel under a vacuum bell jar maintained at ambient temperature. The samples are systematically advanced by rotating the carousel resulting in each sample sequentially falling through a delivery tube containing an inverted ball valve into a sample vaporizing chamber within an oven. An additional pair of sapphire ball valves in communication with the glass vaporizing chamber are sequentially opened and closed in a preprogrammed manner along with the opening and closing of the thermal inverted ball valve and the indexing of the carousel such as to automatically evacuate the glass inlet system within the oven, introduce a new sample and vaporize it and then inject this vapor into a mass spectrometer. Such a system is useful in running large numbers of mass spectrometer analyses of hydrocarbon liquids and the like.
U.S. Pat. No. 5,397,989 to Spraul et al. discloses an NMR spectrometer for the measurement of liquid samples having a probe head exhibiting an upper and a lower support, a connector for a feed conduit for the introduction of a liquid sample into the spectrometer and a connector for a drain conduit for the drainage of the liquid sample out of the spectrometer, a sample tube, arranged between the upper and lower supports, for the acceptance of the fluid sample, whereby the one end of the sample tube is connected to the connector for the feed conduit and the other end to the connector for the drain conduit, exhibits, coaxially to the sample tube, a further tube for the acceptance of a calibration fluid which, on one end, is connected to an additional connector for a feed conduit to introduce the calibration fluid into the spectrometer and, on its other end, to an additional connector for a drain conduit to drain the calibration fluid out of the spectrometer. In this manner, it is possible to measure the sample fluid in a simple fashion, without the previous mixing of additives and, subsequent to the measurement, to regain the sample fluid in its original state, while allowing for the introduction of a calibration fluid for field stabilization and for the quantitative comparison of line intensities.
U.S. Pat. No. 5,705,928 to Haner discloses a sample delivery system for flow-through NMR analysis which utilizes pressurized gas as a means for conveying a sample into and out of an NMR spectrometer. Two sources of gas pressure, a forward pressure and a back pressure, oppose the sample within the tubing of the sample delivery system and the tubing of the flow-through system which are operatively coupled together. Conveyance of a sample in any direction within the tubing is achieved by adjusting the pressure differential. Precise positioning of the sample in the magnetic field and complete removal of the sample from the NMR spectrometer when analysis is complete are achieved by using a signal processor which receives signals from the NMR detector or other detectors positioned along the length of the tubing. These signals provide an indication of the position of the sample in the tubing. The signal processor uses this information to adjust the forward and back pressure, thereby achieving the desired positioning of the sample.
U.S.
Kokubun Daniel N.
McMurtry Gary M.
Chong Leighton K.
Fernandez Kalimah
Lee John R.
Ostrager Chong & Flaherty
Pacific Environmental Technologies
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