Numerical Simulation of Ion Transport in a Nano-Electrospray Ion Source at Atmospheric Pressure
- Science and Technology Facilities Council, Daresbury Laboratory, Scientific Computing Department (United Kingdom)
- Waters Corporation (United Kingdom)
Understanding ion transport properties from the ion source to the mass spectrometer (MS) is essential for optimizing device performance. Numerical simulation helps in understanding of ion transport properties and, furthermore, facilitates instrument design. In contrast to previously reported numerical studies, ion transport simulations in a continuous injection mode whilst considering realistic space-charge effects have been carried out. The flow field was solved using Reynolds-averaged Navier-Stokes (RANS) equations, and a particle-in-cell (PIC) method was applied to solve a time-dependent electric field with local charge density. A series of ion transport simulations were carried out at different cone gas flow rates, ion source currents, and capillary voltages. A force evaluation analysis reveals that the electric force, the drag force, and the Brownian force are the three dominant forces acting on the ions. Both the experimental and simulation results indicate that cone gas flow rates of ≤250 slph (standard liter per hour) are important for high ion transmission efficiency, as higher cone gas flow rates reduce the ion signal significantly. The simulation results also show that the ion transmission efficiency reduces exponentially with an increased ion source current. Additionally, the ion loss due to space-charge effects has been found to be predominant at a higher ion source current, a lower capillary voltage, and a stronger cone gas counterflow. The interaction of the ion driving force, ion opposing force, and ion dispersion is discussed to illustrate ion transport mechanism in the ion source at atmospheric pressure. .
- OSTI ID:
- 22776992
- Journal Information:
- Journal of the American Society for Mass Spectrometry, Vol. 29, Issue 3; Other Information: Copyright (c) 2018 American Society for Mass Spectrometry; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-0305
- Country of Publication:
- United States
- Language:
- English
Similar Records
Characterization of an electrospray ion source as a controlled-current electrolytic cell
Ionization and transmission efficiency in an electrospray ionization-mass spectrometry interface