Applied Rf And Dc Fields; Figure 24. Quadrupole Q2 (Bottom) Separated From The Active Collision Cell Housing; Figure 25. Polarity Of The Rf And Dc Voltages Applied To The Q1 And Q3 Mass Analyzers - Thermo Scientific TSQ Endura Hardware Manual

Applied RF and DC Fields

Thermo Scientific
Quadrupole Q2 is a square-profile quadrupole rod assembly that always acts as an ion
transmission device. The rods bend into a 90-degree arc
reducing the footprint of the instrument, prevent the transmission of unwanted neutral
species to the detector and dramatically lower the noise level in the data.
Quadrupole Q2 has become synonymous with the term active collision cell. Technically, the
collision cell is the chamber that encloses Q2 where CID can take place if the argon or
nitrogen collision gas is present. The active collision cell has an axial field down its length to
speed throughput. This allows up to 500 SRM transitions per second.
Figure 24. Quadrupole Q2 (bottom) separated from the active collision cell housing (top)
EL21, EL22, and
EL23 lenses
In a quadrupole rod assembly, because rods opposite each other in the array connect
electrically, the four rods are considered two pairs of two rods each. The mass spectrometer
applies RF and DC voltages to the rods. As shown in
applied to the four rods are the same, the two pairs are 180 degrees out of phase (that is, one
pair has a positive voltage and the other a negative voltage).

Figure 25. Polarity of the RF and DC voltages applied to the Q1 and Q3 mass analyzers

(Figure
Figure
RF voltage + DC voltage
RF voltage 180° out of phase – DC voltage
TSQ Endura and TSQ Quantiva Hardware Manual
4
Ion Transmission and Mass Analysis
Mass Analyzers
24), which in addition to
EL31, EL32, and
EL33 lenses
25, although the RF voltages
37