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Combined APPI/APCI source 1-11
Combined APPI/APCI source
Atmospheric pressure photoionization (APPI) uses photons generated by a
discharge UV lamp (~10.2 eV) to produce sample ions from vaporized LC
eluent. Direct photoionization of the sample molecule occurs when the photon
energy exceeds the ionization potential of the sample molecule.
The optional dual-mode (APPI/APCI) ionization source comprises an APPI
source enclosure, which is used in conjunction with a standard APCI probe.
You can operate the source in APPI or dual-mode, which switches rapidly
between ionization modes, facilitating high-throughput analyses.
For further details, see the
Waters APPI Source Operator’s Guide Supplement .
IntelliStart Fluidics system
The IntelliStart Fluidics system is built into the instrument; it controls how
sample is delivered to the source.
For standard flow applications, the system delivers sample directly to the
mass spectrometer source in one of three ways:
• From the LC column.
• From three integral reservoir bottles. Use standard reservoir bottles
(30 mL) for instrument setup and calibration. Use low-volume vials
(1.5 mL) to infuse smaller volumes.
Tip:
The reservoir bottles can also deliver sample through direct or
combined infusion to enable optimization at analytical flow rates.
• From a wash reservoir, which contains solvent for automated flushing of
the instrument’s solvent delivery system.
For nanoACQUITY, the valves and pumps that make up the IntelliStart
Fluidics system introduce dead volume, which can cause unacceptable peak
broadening. For this reason, the nanoACQUITY is plumbed directly to the
NanoFlow sprayer using a suitable short piece of silica tubing.
For reference flows for both the LockSpray and NanoLockSpray source, the
IntelliStart Fluidics system delivers lock mass solution from reservoir bottle B
or, for extended operating hours, from a separate, external bottle of lock mass
solution.