Table 2.
Experiments performed using T-infusion or post-column infusion to optimize source parameters
| Experiment | Goal |
|---|---|
| Optimize capillary voltage (ESI) | Optimize the solvent spray from the tip of the ESI probe to optimize ionization efficiency (known as nebulizer/sprayer/ionspray voltage) |
| Optimize corona current (APCI) | Optimize the corona needle discharge current to optimize ionization efficiency |
| Optimize voltage applied to orifice plate/cone | Optimize the voltage that causes ion clusters to break apart before entering the mass spectrometer (cone or capillary voltage/declustering potential) |
| Optimize source temperature | Optimize the temperature to eliminate condensation of aqueous mobile phase components to improve volatilization and reduce matrix components (dependent upon liquid chromatography flow rate and percentage aqueous) |
| Optimize source gas flows | Optimize the gas flow that aids in formation of solvent spray (nebulizer/sheath gas) and optimize gas flow that aids in evaporation of solvents and drives ions into gas phase (desolvation gas) |
| Optimize probe distance from cone | Optimize the distance between the sample probe and/or spray needle and the orifice in the cone |
| Optimize curtain/cone/orifice plate gas flow | Optimize the gas flow that inhibits solvent and non-ionized matrix components from entering the flight tube; use the highest gas flow possible without sacrificing sensitivity |
| Optimize entrance potential | Optimize the voltage used to focus ions on initial ion guide(s) towards quadrupole 1 |
| Optimize collisionally activated dissociation gas | Optimize the pressure of the collision gas in quadrupole 2, which helps focus the ions passing through and aids in dissociation to fragment ions |
| Optimize cell exit potential | Optimize the voltage as ions exit quadrupole 2 to focus them towards quadrupole 3 |
APCI, atmospheric pressure chemical ionization; ESI, electrospray ionization.