Abstract: The invention pertains to methods and apparatus for performing mass spectrometry with reduced noise. In some embodiments, an additional amount of a carrier gas is introduced into a mass spectrometer to reduce the noise.

Abstract: A method is provided for continuously monitoring for the presence or quantity of an analyte in a flowing liquid stream. The method involves binding an analyte-specific receptor species to the surface of a piezoelectric substrate, contacting the surface bound receptor species with the flowing liquid stream and quantitating the presence of the analyte. A novel apparatus for detecting the presence of an analyte in a liquid chromatography eluant is provided as well.

Abstract: A transfer capillary and interface are provided that allow samples from multiple fluid streams to be introduced into a single mass analyzer. The transfer capillary has two or more channels and is placed between a first chamber, in which ions from the multiple fluid streams are generated, and a second chamber that is in fluid communication with a mass analyzer. The interface includes ionizers that generate ionized sample from each fluid stream and that direct the ionized sample toward the channels of the transfer capillary. The transfer capillary includes a multiplex selector that allows ions to flow through a selected subset of channels and sequentially changes which of the channels are included in the subset of channels through which ions flow.

Abstract: The present invention relates to microdevices for introducing a small volume of a fluid sample into an ionization chamber. The microdevices are constructed from a substrate having a first and second opposing surfaces, the substrate having a microchannel formed in the first surface, and a cover plate arranged over the first surface, the cover plate in combination with the microchannel defining a conduit for conveying the sample. A sample inlet port is provided in fluid communication with the microchannel, wherein the sample inlet port allows the fluid sample from an external source to be conveyed in a defined sample flow path that travels, in order, through the sample inlet port, the conduit and a sample outlet port and into the ionization chamber. Optionally, the fluid sample undergoes a chemical or biochemical reaction within an integrated portion of the microdevice before reaching the ionization chamber. A nebulizing means nebulizes the fluid sample in a nebulizing region adjacent to the sample outlet port.

Abstract: A system and method for over the air transmissions over a code division multiple access (CDMA) data channel is provided. A system comprises a data network, a server, and a base station in communication with the data network and configured to receive an update parameter from the server. The base station is further configured to establish a CDMA data channel between the mobile client and the base station, and the base is configured to send the update parameter from the base station to the mobile client over the data channel. The update parameter is sent in accordance with a CDMA air interface standard (such as IS-95) and a CDMA data channel standard for data services (such as IS-707).

Abstract: A transfer capillary and interface are provided that allow samples from multiple fluid streams to be introduced into a single mass analyzer. The transfer capillary has two or more channels and is placed between a first chamber, in which ions from the multiple fluid streams are generated, and a second chamber that is in fluid communication with a mass analyzer. The interface includes ionizers that generate ionized sample from each fluid stream and that direct the ionized sample toward the channels of the transfer capillary. The transfer capillary includes a multiplex selector that allows ions to flow through a selected subset of channels and sequentially changes which of the channels are included in the subset of channels through which ions flow.

Abstract: The present invention relates to microdevices for introducing a small volume of a fluid sample into an ionization chamber. The microdevices are constructed from a substrate having a first and second opposing surfaces, the substrate having a microchannel formed in the first surface, and a cover plate arranged over the first surface, the cover plate in combination with the microchannel defining a conduit for conveying the sample. A sample inlet port is provided in fluid communication with the microchannel, wherein the sample inlet port allows the fluid sample from an external source to be conveyed in a defined sample flow path that travels, in order, through the sample inlet port, the conduit and a sample outlet port and into the ionization chamber. Optionally, the fluid sample undergoes a chemical or biochemical reaction within an integrated portion of the microdevice before reaching the ionization chamber. A nebulizing means nebulizes the fluid sample in a nebulizing region adjacent to the sample outlet port.

Abstract: A system and method for controlling data access by a user device on a network utilizes a subscriber database cataloging the device identity and the corresponding dynamic address. The system includes an interworking function device operative to receive a call from the user device. The user device has a corresponding dynamic address. The interworking function device sends a message to the subscriber database indicating the device identity and the corresponding dynamic address. The sent information is cataloged at the subscriber database to allow the server, when the server receives the corresponding dynamic address, to retrieve the device identity from the subscriber database and to control data access over the network based on the device identity.

Abstract: A technique that modulates the power of a inductively coupled plasma (ICP) according to the operative modes of a spectrometer. An analytical apparatus of the present invention contains an inductively coupled plasma generator (ICPG) and a spectrometer. The ICPG generates a plasma for forming ionic and excited molecular species from a sample. The spectrometer analyzes the ionic and excited molecular species formed. The spectrometer operates in an analysis mode wherein the ionic and excited molecular species are identified according to physical characteristics of the species to provide data on the species and further has a washout mode wherein the spectrometer flushes out interfering ions and molecules and provides no significant data on the sample. The controller modulates the ICPG to operate in power cycles, at each cycle the ICPG operates in an analysis period and a stand-by period. By modulating the plasma power, the power consumption and heat dissipation can be reduced.

Abstract: A technique that modulates the power of a inductively coupled plasma (ICP) according to the operative modes of a spectrometer. An analytical apparatus of the present invention contains an inductively coupled plasma generator (ICPG) and a spectrometer. The ICPG generates a plasma for forming ionic and excited molecular species from a sample. The spectrometer analyzes the ionic and excited molecular species formed. The spectrometer operates in an analysis mode wherein the ionic and excited molecular species are identified according to physical characteristics of the species to provide data on the species and further has a washout mode wherein the spectrometer flushes out interfering ions and molecules and provides no significant data on the sample. The controller modulates the ICPG to operate in power cycles, at each cycle the ICPG operates in an analysis period and a stand-by period. By modulating the plasma power, the power consumption and heat dissipation can be reduced.

Abstract: A system for accurate and precise measurements of analyte(s) in a system. The measurement system comprises piezoelectric surface wave sample devices, at least one piezoelectric surface wave reference device, and the measurement instrument.