Mass Spectrometry

Mass Spectrometry is primarily use to determine the mass of a compound. Also, through fragmentation of the parent compound, information about the structure of a compound can be deduced.

All mass spectrometers analyze ions in the gaseous state. Mass spectrometers are equipped with different ion sources in an effort to generate ions depending on the class of the compound.

For nonvolatile compounds the chemistry department has electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photoionization (APPI) sources. For volatile compounds either chemical ionization (CI), via methanol, or electron ionization (EI) can be done.

The SIL has four instruments with mass spectrometers.

Waters LCMS

A Waters Micromass ZQ quadrupole mass spectrometer suitable for routine reaction monitoring. It has the Waters Alliance e2695 HPLC unit which allows for separation of mixtures before analysis by the mass spectrometer. Samples can be introduced using either the HPLC autosampler or the syringe infusion method. The HPLC is equipped with a Waters XBridge C18 column for general public use; any other column must be provided by a PI.

Waters LCMS

Agilent TOFMS

An Agilent model G6230A high-resolution high-mass accuracy time-of-flight mass spectrometer. This instrument is suitable for final product characterization. It has a mass accuracy of 2 ppm and has ESI, APCI, and APPI ion sources. Samples can only be introduced via the infusion method using a syringe pump. Samples should be in the micro to nanogram per milliliter concentration range.

Agilent TOFMS

Varian GCMS

A Varian CP-3800 gas chromatograph coupled to a Varian Saturn 2200 ion trap mass spectrometer. Setup for analyzing volatile solid samples using the Varian ChromatoProbe. The mass spectrometer can ionize compounds by CI or EI.

Varian GCMS

Agilent GCMS

An Agilent 7890A gas chromatograph coupled to a 5975C quadrupole mass spectrometer. This instrument has a 150 position Agilent 7603 autosampler and has EI only. It can be run without the mass spectrometer using a FID as the detector.

Agilent GCMS