Mass spectrometry

Mass spectrometry is a very sensitive technique and typically only a few micrograms of material are required to allow analysis to be performed.

The instruments of the MS Service cover a range of different types of analysis: Electron Ionisation (EI) can be used to gain structural information via in-source fragmentation on solid samples desorbed from a heated probe or introduced from a GC transfer line.

Electrospray Ionisation (ESI) does not usually cause fragmentation and it can be used on a wide range of predominantly polar compounds to confirm mass and structural formulae of molecular ions. Further structural information is possible when the technique is coupled with tandem mass spectrometry (ESI-MS/MS). Atmospheric Pressure Chemical Ionisation (APCI) also ionizes without causing fragmentation and is mainly used on low mass, non-polar compounds that ESI fails to ionise. These complementary techniques allow ionization to be carried out in both positive and negative modes and both can also be coupled with high performance liquid chromatography (HPLC).

Field Ionisation (FI) and Liquid Injection Field Desorption Ionisation (LIFDI) can provide information on a wide range of volatile and non-volatile, polar and non-polar compounds.

This set of techniques makes it possible to analyse organic, inorganic and organometallic compounds as solids or in solution, in pure form or in mixtures.

Applications of mass spectrometry include the structural identification of reaction products and product components, impurities, additives, pollutants etc as well as structure confirmation and purity checks and the detection of trace components.

The mass spectrometry (MS) service provides support to Chemistry and other University departments and to external customers by means of two MS instruments:

• A Bruker compact^® time of flight mass spectrometer with ESI and APCI capabilities along with the option to perform MS/MS measurements. This is coupled to an Agilent 1260 Infinity series LC system providing automated high throughput sample delivery and the facility for accurate mass ESI/APCI-MS and LC-MS measurements
• A JEOL AccuTOF GCx-plus mass spectrometer, optionally coupled to an Agilent 7890B GC system.  These instruments allow the analysis of solids, liquids and gases and provide accurate mass EI measurements, and potential compound identification through comparison of EI spectra with NIST libraries, along with GC-FI and LIFDI measurements

Contact

Mr Karl Heaton
Tel: +44 (0)1904 322591
Email: karl.heaton@york.ac.uk