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 Atmospheric Pressure Ionization ThermoFinnigan LCQ –Classic
Ion Trap Mass Spectrometer is located in Room 1203 Micromass Quattro II
- Triple Quadrupole Mass Spectrometer is located in Room 1203 The ThermoFinnigan LCQ - Classic and Micromass Quattro II, dedicated API-LC/MS instruments are located in room 1203 of the Henry Eyring Chemistry Building (North). Both instruments are used for research support. Individual operation of the LCQ-Classic or the Quattro II is encouraged after a small checkout procedure. Columns, solvents are consumables are to be provided by the researcher. Costs for any consumable items provided by the facility will be charged to the submitter. Features
ESI is a soft ionization technique and like FAB and CI provides quasimolecular information. The samples are first desalted and made detergent free. Acids such as formic and acetic are permissible to adjust the pH. Where TFA is necessary for chromatographic separation low levels are allowed (<0.1% v/v). Non-volatile buffers and salts will result in suppression of the signal and result in a costly waste of time. Analytes with molecular weights below 1000 amu will result in singly charge ions (MH+) whereas larger species will produce multiply charged ions allowing for the determination of samples up to 100k daltons. ESI is used for the analysis of large polar compounds including but not limited to proteins, peptides and oligonucleotides.
APCI like classical CI gives quasimolecular
information with minimal or no fragmentation.
The neutral sample is sprayed through a capillary tube into the API
chamber. The discharge from a
corona discharge needle provides the CI effect using the aqueous solvent as the
source of protonation. APCI does
not provide multiple charging. Consequently
the maximum allowable mass is limited by the instrument upper scanning limit.
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For information on the Mass Spectrometry Facility, please contact:
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