Organic Mass Spectrometry Suite (OMSS)

Facilities for the separation and measurement of organic molecules using liquid and gas chromatography coupled with various types of detectors

The Organic Mass Spectrometry Suite (OMSS) comprises analytical instrumentation in three laboratories for the separation, detection, identification and quantification of volatile and semi-volatile organic molecules.

OMSS offers facilities for the separation and measurement of organic molecules (molecules mainly comprising carbon and hydrogen, but nitrogen, sulfur and oxygen containing species too) using liquid and gas chromatography coupled with various types of detectors. This instrumentation is used for undergraduate teaching, undergraduate project work, postgraduate research and commercial activities.

Typically, analysis is undertaken on whole samples or refined fractions of samples prepared by extraction and chromatographic ‘clean-up’, and possibly derivatisation, in our well-appointed ‘wet’ chemistry laboratories. You can use our decision tree to help identify the best instrumentation for your analysis. Our facilities are co-located in open teaching spaces with undergraduate access and dedicated research laboratories.

(

Location: Davy Building

About us

We have a broad range of instrumentation to enable analysis of diverse analytes in different matrices. These include gases, lipids, waxes, pollutants, pharmaceuticals and polymers with a spectrum of applications in environmental assessment and paleo-temperature reconstructions, flow assurance issues, contamination assessment, climate studies, materials characterisation and health studies. Training in the use of instrumentation is provided for undergraduate and postgraduate students. Our staff can provide bespoke commercial services.

Liquid chromatography

Our liquid chromatography (LC) instrumentation includes preparative to analytical scale high- and ultrahigh-performance liquid chromatographs (HPLC and uHPLC) coupled with various detectors including ultraviolet/visible (UV/vis), refractive index (RI), evaporative light scattering (ELS) and an Orbitrap™ mass spectrometer (MS).

The LCs can be operated in reverse-phase (polar mobile phase/non-polar stationary phase) or normal-phase (non-polar mobile phase/polar stationary phase) modes to carry out a wide range of separations. Our Orbitrap™ MS can be interfaced with the LC system via a heated electrospray ionisation (HESI), atmospheric pressure chemical ionisation (APCI) or atmospheric pressure photo-ionisation (APPI) probe, dependent upon application, and provides accurate mass data with +/-5 parts per million (ppm) mass accuracy. The Orbitrap™ MS also has an atmospheric solids analysis probe (ASAP) to undertake direct analysis of solids or dilute solutions.

Gas chromatography

Our gas chromatography (GC) instrumentation includes four electronic pneumatic control (EPC) gas chromatographs with flame ionisation detectors (FID), one with additional nitrogen-phosphorus detector (NPD) and two set up for high temperature (HTGC) analysis capable of detecting compounds with up to around 100 carbon atoms. (HT)GC-FID is the preferred technique for quantitative studies.

For gas analysis we have a greenhouse gas (GHG) GC with FID, thermal conductivity (TCD) and electron capture (ECD) detectors. The ECD is used to detect the GHG nitrous oxide (N2O) and can also measure halogenated compounds, such as chlorofluorocarbons (CFCs). Volatile gases, such as amines, can be measured using solid phase micro extraction (SPME) and quantification by NPD. The GHG and volatile gas analysis is fully automated, including the SPME process, and can facilitate gas liquid and headspace analysis.

We have four GCs coupled with mass spectrometers (GC-MS) which are used to aid identification of individual analytes. Three of the systems have quadrupole mass spectrometers (one utilising hydrogen carrier gas which provides optimum resolution in the GC separation) and one, capable of operating as HTGC-MS, uses a tunable electron voltage (12 to 70 eV) Time-of-Flight MS which can be useful to help identify molecular ions. Our suite includes a pyrolysis/UV irradiation-thermal desorption-GCxGC-Time-of-Flight-tandem ionisation Select eV mass spectrometer (py/UVi-TD-GCxGC-ToF-TI-MS).

This instrument provides a flexible format for sample introduction via liquid injection, transfer of pyrolysis or UV irradiation effluent) or desorption of samples collected on TD tubes offline. The TD system can also be used to concentrate vapours from pyrolysis/UV irradiation. GCxGC provides excellent separation of analytes in two dimensions (separation efficiency is the product of separation efficiency in both dimensions) whilst the tandem ionisation allows collection of low (12 eV) and high (70 eV) spectra in a single analysis.