INSTRUMENT NAME: Micromass GCT GC/EI-CI Time-of-Flight Mass Spectrometer
INSTALLATION DATE: January 2001
OPERATOR: Andreas Breidbach
SYNOPSIS: We acquired our GCT in January of 2001. Both EI and
CI sources are routinely used either coupled to the GC or with the solid
probe system. The high resolution of the instrument [7000 RMS] coupled
with the exact mass [< 5ppm] obtained with only one internal calibrant
mass allows for elemental composition to be performed on complex mixtures
separated by the gas chromatograph. The instrument thus plays a large
role for students and staff of the chemistry department. The original
idea behind the purchase of this instrument was to encourage graduate
students to run their own exact mass samples. However, due to the high
maintenance levels required of the GCT, there are three dedicated
operators in the lab and others are discouraged from operating the
instrument. Biological quantification assays are also performed,
although the instrument has a limited dynamic range, on many compounds
including cholesterol, polyamines, gamma-hydroxybutyrate, and
steroids. A novel method for analyzing polyamines by negative mode
CI has been developed using this instrument. The GCT also plays a
large role in Professor Kym Faull’s introductory mass spectrometry
class [C108/C208, Mass Spectrometry for Chemists and Biochemists,
taught each winter quarter]. The class learns the basics of gas
chromatography, electron impact ionization and chemical ionization,
and orthogonal time-of-flight analysis by running various biological
samples and, as the final lab, a sample of their own urine.
PLEASE REFERENCE GRANT NUMBER CHE 0078299 FROM THE
NATIONAL SCIENCE FOUNDATION IN ALL PUBLICATIONS USING DATA AQCUIRED ON THE
GCT. THANK YOU!