Waters Quattro Premier XE, Operator'S Manual, Page: 17 / 86

APCI mode 1-3
APCI mode
Atmospheric Pressure Chemical Ionization (APCI) produces singly-charged
protonated or deprotonated molecules for a large range of nonvolatile
analytes.
In APCI mode, the source fitted with an APCI corona pin. The APPI lamp
drive assembly is not used, and is retracted from the source.
APCI mode
The APCI 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.
APCI probe
Retracted APPI lamp drive
assembly
Sample cone
APCI corona pin