Because they traverse that zone at a different angle they also enter the normalisation chamber differently, and because the entrance to that last chamber is a 1 cm-diameter hole, and the flight distances are 70 cm (lens-collision zone) and 30 cm (collision zone-normalisation), different fractions of the beam reach the normalisation zone when the velocity is changed.
This modeling proposed here may help to design new types of electron guns and applications using cylinder and aperture lenses in collision experiments.
Peptides were quantified using SRM in positive ion mode under the following conditions: ionization voltage, 3500 V; sheath gas pressure, 10 arbitrary units; auxiliary gas pressure, 1 arbitrary units; capillary temperature, 270°C; Tube lens offset, 92; Collision pressure, 1.5.
The multiple-reaction-monitored parameters were optimized through post-column infusion of the stock solution (1 μg/mL) using Quantum TuneMaster software (ThermoFisher).The parameters included tube lens (72.3) and collision energy (27 V) for imipenem transition (m/z 300.1 > 142.2).
Positive ion mass spectra were acquired in SRM mode under the following parameters: capillary spray voltage, 1.9 kV; capillary temperature, 250 °C; ion source discharge current, 4.0 A; S-lens, 163 V; collision gas, argon at 15 psi; Q1/Q3 peak width, 0.7 Da; and cycle time, 2 s.
It shows the end of the electric guide (the lens) on the left, the collision zone in the center, and the density normalisation region on the right.
The latter characteristic allows us to measure turbine blades surfaces with large curvature without collisions between the lens and the measurement object.
The MRM transitions for each analyte, their respective collision energy, and tube lens values were reported in Table 1(b).
The parent ion m/z, fragment ion m/z, collision energy, and tube lens voltage for the two compounds were 296.1 m/z.
The selected reaction monitoring (SRM) transitions for each analyte, their respective collision energy, and tube lens values were reported in Table 1(a).
