Mass Spectrometry

The Molecular Organic Analysis Laboratory- at the Geophysical Laboratory.

Why Mass spectrometry? We do many different experiments at the Geophysical Laboratory involving organic molecules, many of our experiments attempt to simulate ancient Earth environments as well as extraterrestrial environments. We have also interrogated the results of experiments from very high pressures (e.g. up to 20 GPa and beyond) and have detected clearly defined organic products, e.g. benzene oligomers (up to tetramers). In order to follow the progress of organic reactions during our experiments we need the ability to interogate our experimental products- what molecules formed, what molecules were destroyed. Towards this end we have available to us a wide array of instrumentation- in particular a highly functional structural mass spectrometry facility in the Molecular Organic Analysis Laboratory and including some fine inherited instruments that are in great working shape.

Mass Spectrometers: Work Horses in Organic Analytics

We currently have three Gas chromatographs interfaced with Quadrupole Mass spectrometers that are fully functional, we have one ancient HP GCMS that is totally recoverable (if we ever needed a fourth). We have one Liquid Chromatograph interfaced with a Diode Array detector for UV-Vis and a tandem quadrupole mass analyser for a range of mass spect experiments- very powerful!

In the Molecular Organic Analysis Laboratory we have the following GC-MS's and one LC-MS-MS:

1) GC-MS System 1 (my first GCMS!): This is a HP (now Agilent) 6890 series GC interfaced with a 5972 quadrupole mass spectrometer. This instrument also is configured to do Chemical Ionization (it has the CI source and CI gases). This was the first GC-MS that I acquired and is yet still a great machine- a testimony to HP (now Agilent) and this line of GC-MS's- The only funny thing is that the GCMS thinks that it inhabits the year 1995 (it can only operate using Windows 95- so we have made some work arounds- it not easy to use and not recommended for routine use). Aside from the CI source if you need it, we augmented this GC-MS with a CDS 1000 pyroprobe with heated injector interface. This is a very handy accessory providing pyrolytic analysis of organic solids (maximum heating rate is 500 °C/second up to temperatures in excess of 1000 °C). We use the pyroprobe for studies of complex organic polymers involving ancient biomacromolecules, extraterrestrial organic solids, and experimental studies of the formation of extraterrestrial solids.

2) GC-MS System 2: This is an Agilent 6890N series GC interfaced with a 5973N quadrupole mass spectrometer. This instrument has a model 7483, 60 well auto sampler. This is really a step up from GCMS # 1 and most would choose to use this for their analysis and most do- it is a great instrument.

3) GC-MS System 3: Our newest instrument: an Agilent 7890 series GC interfaced with a 5975 inert quadrupole mass spectrometer and an autosampler. This is yet a major step up from GCMS # 2 and anyone with any sense would choose to use this over any of our older machines- this is a really fine GC-MS. Yes Agilent continues to improve on their amazing instruments and this GCMS is (for us) the next leap forward.

4) LC-MS-MS System 4: This instrument is unique amongst the bunch and really amazing. This is a Waters Aquity Ultra-performance LC (UPLC) that is plumbed first through a diode array detector (UV-Vis vs time from 220 nm to 700 nm) and then into an electrospray ionization source of a tandem quadrupole mass analyzer (MS-MS, where MS1 leads to a traveling wave guide collision chamber then on to MS2). This instrument can literally find the molecular needle in a haystack. It is a very powerful analytical instrument.

Other Mass Spects: Other mass organic focused mass spectrometers that we maintain and use include three instruments that were obtained by former colleague Dr. Marilyn Fogel and that she left with us when she left GL to join the faculty in the UCal system (first Merced- now Riverside). Marilyn Fogel is one of the real pioneers of the field of biogeochemistry and the was an early contributor to the use of stable isotope biogeochemistry, later she obtained a very interesting instrument that is a potential mover and shaker in environmental proteomics. These instruments are up and running maintained by colleague Dionysis Foustoukos and available for use/collaboration.

Isotope Ratio Mass spectrometer # 1:

This is a Thermo Deltaplus spectrometer with an Elementar "Cube" interface.

Isotope Ratio Mass spectrometer # 2:

This is a Delta V (old unit- still works!) Interfaced with a Thermoquest GC combustion unit for GC-IRMS.