Method 6040E (2-Methylisoborneol (MIB) and Geosmin) is used for the analysis of taste and odor compounds inclusive of 2-methylisoborneol (MIB) and geosmin. The method consists of three primary steps. The process consists of a microextraction procedure followed by the separation and then mass identification of the compounds. The compounds are volatilized and collected using solid-phase microextraction (SPME) fiber. The fiber consists of a fiber coated with divinylbenzene-carboxen-polydimethylsiloxane cross-link. The fiber is placed in the headspace above the sample in a closed vessel and allowed to equilibrate with the aqueous sample. The fiber is then removed from the headspace and inserted directly into the heated injection port on the gas chromatograph (GC) where the analytes are allowed to desorb into the GC column. The column provides the separation of the analytes of interest from background interferences. The compounds are then identified by a mass spectrometer.
The technique discussed above allows the laboratory to be extremely accurate in the determination of the analytes and highly precise in the concentration of each compound.