Abstract: A method and apparatus are disclosed wherein a plurality of electric fields and of orthogonal spray configurations of vaporized analyte are so combined as to enhance the efficiency of analyte detection and mass analysis. The invention provides reduced noise and increased signal sensitivity in both API electrospray and APCI operating modes.

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: A method and apparatus are disclosed wherein a plurality of electric fields and of orthogonal spray configurations of vaporized analyte are so combined as to enhance the efficiency of analyte detection and mass analysis. The invention provides reduced noise and increased signal sensitivity in both API electrospray and APCI operating modes.

Abstract: The invention provides a microanalytical device for analyzing a fluid sample containing at least one analyte molecule. The device is constructed from a substrate and a cover plate each having a substantially planar surface and a microchannel formed therein. The cover plate is placed over the substrate such that the cover plate microchannel is arranged in opposing relationship with the substrate microchannel. A membrane is interposed between the substrate and the cover and has at least one pore sized to allow passage of the analyte molecule from the substrate microchannel to the cover plate microchannel. An analyte altering moiety is attached to an interior surface of the pore and is capable of chemically altering the analyte molecule. Also disclosed are a method for chemically altering and transporting an analyte molecule in a fluid and a method for identifying a plurality of biomolecules.

Abstract: A method is provided for the separation of nucleic acid samples. The method includes: providing a test mixture of a plurality of nucleic acid samples, wherein each sample is labeled with a spectrally detectable tag; applying the test mixture to a reversed phase solid support; eluting the mixture under partially denaturing conditions; and detecting spectrally resolved signals produced by the nucleic acid samples labeled with the detectable tags.

Abstract: The invention teaches the uses of a plurality of electric fields and of orthogonal spray configurations of vaporized analyte which combine so as to operate to enhance the efficiency of analyte detection and mass analysis with a mass spectrometer by reducing vapor in the vacuum system and concomitant noise. Several embodiments of the invention are described for purposes of illustration.

Abstract: Close coupled momentum separator with integral removable source volume for particle beam liquid chromatography/mass spectrometry is provided. The inventive PB LC/MS system comprises a momentum separator wherein the skimmers are designed to accommodate the particle beam conical dispersion so as to minimize the number of particles lost in the separator. In addition, the exit of the momentum separator is closely coupled to the entrance of the MS source volume. The PB LC/MS system demonstrates improved linearity in signal and enhanced sensitivity.

Abstract: A liquid chromatography-mass spectrometry system that can be configured as either a particle beam or an electrospray interface is provided. The device incorporates structural elements that are common to both interfaces thereby eliminating the need to have two completely separate ES and PB LC/MS systems. The LC/MS device according to the present invention generally comprises a momentum separator, nozzle housing, mass spectrometer, and a vacuum subsystem. A mass spectrometer housing encloses a quadrupole mass analyzer. When used in the ES mode, and ES source module is coupled into the inventive device. Similarly, when used in the PB mode, a PB source module is coupled into the inventive device along with a separate source PB probe. The mass analyzer chamber can accommodate a particle beam source probe for generating ions from analyte particles. In either mode, the modules can consist of commercially available interfaces modified for use with the inventive device.

Abstract: Close coupled momentum separator with integral removable source volume for particle beam liquid chromatography/mass spectrometry is provided. The inventive PB LC/MS system comprises a momentum separator wherein the skimmers are designed to accommodate the particle beam conical dispersion so as to minimize the number of particles lost in the separator. In addition, the exit of the momentum separator is closely coupled to the entrance of the MS source volume. The PB LC/MS system demonstrates improved linearity in signal and enhanced sensitivity.

Abstract: A mixture of fluorescently-excitable amino acid derivatives suitable for use in quantitative amino acid analysis is provided in which primary amino acids are present as derivatives of a first reagent and secondary amino acids are present as derivatives of a second different reagent. The process for preparing the mixture comprises the steps of derivatization of the primary amino acids of an amino acid sample with ortho-phthalaldehyde (OPA) and of derivatization of the secondary amino acids of the sample with fluorenylmethylchloroformate (FMOC) in the presence of acetonitrile. The mixture can be obtained automatically and is highly suitable for fast analysis by reversed-phase liquid chromatography.

Abstract: .[.The invention teaches the uses of a plurality of electric fields and of orthogonal spray configurations of vaporized analyte which combine so as to operate to enhance the efficiency of analyte detection and mass analysis with a mass spectrometer by reducing vapor in the vacuum system and concomitant noise. Several embodiments of the invention are described for purposes of illustration..]. .Iadd.The invention relates to a method and apparatus for improving signal relative to noise without loss of ion collection efficiency in electrospray mass spectrometry, including liquid chromatography/mass spectrometry..Iaddend.