Abstract: A metal-channel conversion dynode comprises: a wafer comprising a first face and a second face parallel to the first face and having a thickness less than 1000 ?m; and a plurality of channels passing through the wafer from the first face to the second face at an angle to a plane of the first face and a plane of the second face. In some embodiments, each inter-channel distance may be substantially the same as the wafer thickness. In some embodiments, the wafer is fabricated from tungsten. In some other embodiments, the wafer comprises a non-electrically conductive material that is fabricated by three-dimensional (3D) printing or other means and that is coated, on its faces and within its channels, with a metal or suitably conductive coating that produces secondary electrons upon impact by either positive or negative ions.

Abstract: A metal-channel conversion dynode comprises: a wafer comprising a first face and a second face parallel to the first face and having a thickness less than 1000 ?m; and a plurality of channels passing through the wafer from the first face to the second face at an angle to a plane of the first face and a plane of the second face. In some embodiments, each inter-channel distance may be substantially the same as the wafer thickness. In some embodiments, the wafer is fabricated from tungsten. In some other embodiments, the wafer comprises a non-electrically conductive material that is fabricated by three-dimensional (3D) printing or other means and that is coated, on its faces and within its channels, with a metal or suitably conductive coating that produces secondary electrons upon impact by either positive or negative ions.

Abstract: A system includes an optical measurement unit that measures an optical property of a whole blood sample deposited on a surface of a substrate, an ion source that causes ions derived from the whole blood sample, including ions formed from an analyte of interest present in the whole blood sample, to be emitted from the substrate, a mass analyzer that receives the ions emitted from the substrate and measures an abundance of at least one ion species corresponding to the analyte of interest, and at least one computing device that determines, based on the measured optical property, a hematocrit of the whole blood sample, and determines, based on the determined hematocrit of the whole blood sample and the measured abundance of the at least one ion species, a concentration of the analyte of interest per unit volume of blood plasma.

Abstract: A metal-channel conversion dynode comprises: a wafer comprising a first face and a second face parallel to the first face and having a thickness less than 1000 ?m; and a plurality of channels passing through the wafer from the first face to the second face at an angle to a plane of the first face and a plane of the second face. In some embodiments, each inter-channel distance may be substantially the same as the wafer thickness. In some embodiments, the wafer is fabricated from tungsten. In some other embodiments, the wafer comprises a non-electrically conductive material that is fabricated by three-dimensional (3D) printing or other means and that is coated, on its faces and within its channels, with a metal or suitably conductive coating that produces secondary electrons upon impact by either positive or negative ions.

Abstract: A system includes an optical measurement unit that measures an optical property of a whole blood sample deposited on a surface of a substrate, an ion source that causes ions derived from the whole blood sample, including ions formed from an analyte of interest present in the whole blood sample, to be emitted from the substrate, a mass analyzer that receives the ions emitted from the substrate and measures an abundance of at least one ion species corresponding to the analyte of interest, and at least one computing device that determines, based on the measured optical property, a hematocrit of the whole blood sample, and determines, based on the determined hematocrit of the whole blood sample and the measured abundance of the at least one ion species, a concentration of the analyte of interest per unit volume of blood plasma.

Abstract: A mass spectrometer system can include a vacuum manifold and a high vacuum pump. The vacuum manifold can include a foreline chamber and a high vacuum chamber. The foreline chamber can have a source inlet, a foreline inlet, and a foreline outlet. The high vacuum pump can have a vacuum port coupled to high vacuum chamber, and a foreline port coupled to the foreline inlet.

Abstract: A method is described for identifying the occurrence and location of charging of ion optic devices arranged along the ion path of a mass spectrometer. The method includes repeatedly performing a sequence of introducing a beam of discharge ions to a location on the ion path, and subsequently measuring the intensities of opposite-polarity sample ions delivered to a mass analyzer, with the discharge ions being delivered to a location further downstream in the ion path at each successive sequence.

Abstract: A method is described for identifying the occurrence and location of charging of ion optic devices arranged along the ion path of a mass spectrometer. The method includes repeatedly performing a sequence of introducing a beam of discharge ions to a location on the ion path, and subsequently measuring the intensities of opposite-polarity sample ions delivered to a mass analyzer, with the discharge ions being delivered to a location further downstream in the ion path at each successive sequence.

Abstract: Multipole rod assemblies for guiding or trapping ions in a mass spectrometer. A multipole rod assembly includes a plurality of modules. Each module includes a shield element, one or more insulating elements coupled to the shield element, and one or more multipole rods mounted on the insulating elements, wherein the modules are coupled together to form the multipole rod assembly such that the multipole rods of the modules define an interior volume for guiding or trapping ions.

Abstract: Multipole rod assemblies for guiding or trapping ions in a mass spectrometer. A multipole rod assembly includes a plurality of modules. Each module includes a shield element, one or more insulating elements coupled to the shield element, and one or more multipole rods mounted on the insulating elements, wherein the modules are coupled together to form the multipole rod assembly such that the multipole rods of the modules define an interior volume for guiding or trapping ions.

Abstract: A multiple-pole electrode assembly is disclosed for use in mass spectrometers or other applications such as ion traps or ion guides. The disclosed apparatus provides a rod mounting and connection assembly in which equally spaced rectangular rods are embedded in spaced, dimensionally stable insulating materials. This structure is more conveniently and inexpensively manufactured than previously available multiple pole electrode assemblies.