Waters Xevo TQD, Operator'S, Overview And Maintenance Manual

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3-10 Changing the Mode of Operation
APCI operation
The atmospheric pressure chemical ionization (APCI) mode produces singly
charged protonated or deprotonated molecules for a large range of nonvolatile
analytes. In APCI mode, the source is fitted with an APCI corona pin. Unused,
the APPI lamp drive assembly is retracted from the source.
APCI mode:
The IonSABRE II probe introduces vaporized sample into the source. The
sample passes between the sample cone and the corona pin, which typically
operates with a discharge current of 5 µA. The corona discharge generates
ions that react with the mobile phase molecules to produce stable reagent
ions. Analyte molecules in the mobile phase react with the reagent ions at
atmospheric pressure and become protonated (in the positive ion mode) or
deprotonated (in the negative ion mode). The sample and reagent ions pass
through the sample cone.
IonSABRE II probe
Retracted APPI lamp drive
assembly
Sample cone
APCI corona pin