Technical data

Overview 1
Electrospray ionization (ESI) and Dual ESI
Agilent 6200 Series TOF and 6500 Series Q-TOF LC/MS System Concepts Guide 17
Electrospray ionization (ESI) and Dual ESI
You control the spray chamber
parameters (nebulizer pressure,
drying gas flow and temperature,
and capillary voltage) when you set
up a method in the Method and
Run Control view, described in
Chapter 4.
Electrospray ionization relies in part on chemistry to generate
analyte ions in solution before the analyte reaches the mass
spectrometer. As shown in Figure 1, the LC eluent is sprayed
(nebulized) into a spray chamber at atmospheric pressure in the
presence of a strong electrostatic field and heated drying gas.
The electrostatic field occurs between the nebulizer, which is at
ground in the Agilent design, and the capillary, which is at high
voltage.
The spray occurs at right angles to the capillary. This design
reduces background noise from droplets, increases sensitivity,
and keeps the capillary cleaner for a longer period of time.
Electrospray ionization (ESI) consists of four steps:
Figure 1 Electrospray ion source
HPLC inlet
nebulizer
capillary
solvent
spray
heated drying gas
For Dual ESI, a
second nebulizer is
utilized for the
introduction of
reference mass
ions. From an
ionization
perspective, the
mechanism is the
same.