Ionization techniques and source probes 1-7
Ionization techniques and source probes
Electrospray ionization (ESI)
In electrospray ionization (ESI), a strong electrical charge is given the eluent
as it emerges from a nebulizer. The droplets that compose the resultant
aerosol undergo a reduction in size (solvent evaporation). As solvent continues
to evaporate, the charge density increases until the droplet surfaces eject ions
(ion evaporation). The ions can be singly or multiply charged. The multiply
charged ions are of particular interest because the instrument separates them
according to their mass-to-charge ratios (m/z), permitting the detection of
high-molecular-weight compounds.
The instrument can accommodate eluent flow rates of up to 1 mL/min.
Combined ESI and APCI (ESCi)
Combined electrospray ionization and atmospheric pressure chemical
ionization (ESCi) is supplied as standard equipment on the instrument. In
ESCi, the standard ESI probe is used in conjunction with a corona pin to allow
alternating acquisition of ESI and APCI ionization data, facilitating high
throughput and wider compound coverage.
ESCi mode
Sample cone tip
ESI probe tip
Corona pin
To Next Page
Loading...
