Most of the organic analyses that we conduct are for organic priority pollutants such as pesticides, PCBs, PAHs, BTEX, and other petroleum products. Gas Chromatography (GC) is the standard methodology. From sample matrices such as soil, water, plants and fish, the analytes are extracted into organic solvents, separated from interfering substances (cleaned up), concentrated and run on the GCs.
Using a variety of different detectors, excellent sensitivity and specificity can be achieved for a whole spectrum of organic compounds. The use of automated sample carousels means that the GCs can be left unattended for overnight operation.
The ASU possesses ten automated Gas Chromatography systems: 6 Hewlett Packard and 2 Varian GCs with detectors including FID, ECD, TCD and NPD, and two GCs with mass selective (MS) detectors: a Hewlett Packard 5890 GC with mass selective detector and a Varian 4000 GC with a mass selective detector. Two GCs are equipped with Tekmar 'purge and trap' units.
'Purge and Trap' GC/MS is used to look at volatile organic compounds. Typically, the organic compounds have to be concentrated prior to analysis and this is done by purging the analytes of interest from a sample using an inert gas. This purging process removes the compounds from the sample matrix and deposits them to an absorbent cartridge. This is then heated rapidly and the organics are removed into the GC/MS system in concentrated form.