Abstract: A quadrupole electrode assembly for a mass spectrometer and a method for forming the electrode assembly are provided. The quadrupole electrode assembly is comprised of an elongate outer tube, having an internal surface and an external surface wherein the outer tube is the outermost structure of the electrode assembly and supports a vacuum, and an electrode structure fused to the internal surface of the outer tube. Typically, there are four electrodes where each electrode includes an arced region having a conductive surface. The arced regions of the electrodes are aligned in parallel opposing pairs equidistant from a central axis. The four electrode structures can be four cylindrical glass tubes where the curvature of the arced region approximates a hyperbola. At least a portion of the surface of the arced region is a conductive region typically formed by applying a metal coating to the surface of the glass tube.

Abstract: The present invention provides a method and apparatus for formation of a quadrupole electrode assembly for a mass spectrometer. The quadrupole electrode assembly is comprised of an outer elongate tube having an internal and external surface where the outer elongate tube as the outermost structure may be used for supporting a vacuum and an electrode structure fused to the internal surface of the outer elongate tube. Typically there are four electrodes where each electrode includes an arced region having a conductive surface where the arcs are aligned in parallel opposing pairs equidistant from a central axis. In the preferred embodiment, the four electrode structures are four cylindrical glass tubes where the curvature of the arc approximates a hyperbola. At least a portion of the surface of the arc is a conductive region typically formed by applying a metal coating to the surface of the glass tube.

Abstract: In a gas chromatograph/mass spectrometer (GC/MS) instrument, an improved heating system includes an interface between the gas chromatograph and mass spectrometer portions of the instrument, a radiator located within a vacuum chamber of the mass spectrometer, a thermal coupler attaching the interface to the radiator, and a heat source which directly heats the interface and indirectly heats the radiator via conduction through the thermal coupler. The heating system uses a single heating element located externally to the vacuum system of the mass spectrometer to produce a multiplicity of temperatures for the interface and various portions of the mass spectrometer.