Advantages of reduced noise with the Agilent 500 Ion Trap LC/MS Ion Optics. The API interface and ion coupling optics in the 500 Ion Trap have unique features that reduce the chemical noise from the solvent. The ion guide axis is tilted at an angle so that large solvent clusters and micro droplets pass through the ion guide and do not enter the coupling optics, eliminating large noise spikes in the spectrum. The ion coupling and gating optics further eliminate high energy, multiply charged ion clusters from entering the mass analyzer. The cross section of the coupling optics show ions leaving the API interface capillary and passing through the skimmer cone into the ion guide where collisions with the surrounding gas thermalize their kinetic energies. Ions exiting the ion guide in one section of the vacuum chamber are focused into a second lower pressure region of the vacuum system by the 'ion guide exit' and 'ion guide focus' lens.
This document provides a technical overview of the API interface and ion coupling optics in the Agilent 500 Ion Trap. It details how the tilted ion guide axis allows large solvent clusters and micro droplets to pass through without entering the coupling optics, thereby eliminating large noise spikes in the spectrum.
The ion guide axis is tilted at an angle so that large solvent clusters and micro droplets pass through the ion guide without entering the coupling optics.
Competitors require very large voltages in excess of several thousand electron volts, which causes electrical breakdown.
The deflector lens gating uses a much lower flow rate of 2 L/min for the dry gas.