Ionization Techniques And Source Probes; Electrospray Ionization (Esi); Combined Esi And Apci (Esci); Atmospheric Pressure Chemical Ionization (Apci) - Waters Xevo TQD Operator's, Overview And Maintenance Manual

Ionization techniques and source probes

Electrospray ionization (ESI)

In electrospray ionization (ESI), a strong electrical charge is applied to 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 standard ESI probe accommodates eluent flow rates as high as 2 mL/min,
making it suitable for LC applications in the range 100 µL/min to 2 mL/min.
See page 3-2

Combined ESI and APCI (ESCi)

Combined electrospray ionization and atmospheric pressure chemical
ionization (ESCi) is supplied as standard equipment on the mass
spectrometer. 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.
See page 3-5

Atmospheric pressure chemical ionization (APCI)

A dedicated high-performance APCI interface is offered as an option. APCI
produces singly charged protonated or deprotonated molecules for a broad
range of nonvolatile analytes.
The APCI interface consists of the ESI/APCI/ESCi enclosure fitted with a
corona pin and an IonSABRE II probe.
See page 3-5

Dual-mode APPI/APCI source

The optional, combined atmospheric pressure photoionization/atmospheric
pressure chemical ionization (APPI/APCI) source comprises an IonSABRE II
probe and the APPI lamp drive assembly. The APPI lamp drive assembly
comprises a UV lamp and a repeller electrode. In addition, a specially shaped,
dual, APPI/APCI corona pin can be used. You can operate the source in APPI,
for further details.
for further details.
for further details.
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