Abstract: A collision cell has a plurality of rod electrodes arranged in opposed pairs around an axial centerline and a plurality of drag vanes arranged in the interstitial spaces between the rod electrodes. Operating the collision cell includes, applying a rod offset voltage to the rod electrodes, and varying an offset voltage applied to the drag vanes to identify a vane offset voltage with a maximum intensity for the transition. The method further includes varying a drag field by adjusting the voltages applied to drag vane terminals in opposite directions to identify a drag field value with a cross talk below a cross talk threshold, varying the vane offset voltage by adjusting the voltages applied to the drag vane terminals to maximize the intensity of the transition while preserving the drag field, and operating the collision cell at the vane offset voltage and drag field to monitor the transition.

Abstract: A three section linear or two-dimensional (2D) quadrupole ion trap as a high performance mass spectrometer is described. Mass analysis is performed by ejecting ions radically out a slot formed in one of the rods using the mass selective instability mode of operation. The slot geometry is optimized to yield high ejection efficiencies. Resolution can be controlled by using appropriate end section potentials to control the axial spread of the ion cloud. Multiple detectors can be used for enhancing sensitivity and for enabling enhanced ion analysis techniques in the ion trap.

Abstract: A liquid sample analyzer with a flow-through liquid waveguide cell is described. The light source is fiber coupled to a liquid waveguide or light pipe. The light pipe can be remotely located and fiber coupled to the spectrometer so that the light source is thermally isolated making the spectrometer easily thermally stabilized, and the dispersion minimized. The liquid waveguide cell includes a light pipe that has a lower index of refraction than the liquid flowing through the light pipe. Light is input into the liquid waveguide by an optical fiber that is coupled to the liquid waveguide. The optical fiber diameter and the light pipe core diameter and spacing are selected to provide coupling of all light modes transmitted through the optical fiber into the light pipe. The output light is received by an optical fiber which is arranged to receive all of the light transmitted through the light pipe.