Method 6040E Testing
Method 6040E is used to analyze 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. It is then placed in the headspace above the sample in a closed vessel. This allows the fibers to equilibrate with the aqueous sample.
Sample Separation and Identification
The fiber is then removed from the headspace and inserted directly into the heated injection port on the gas chromatograph (GC). This allows the analytes to desorb into the GC column. The column provides the separation of the analytes of interest from background interferences. Once this is complete, the compounds will be identified. The method for identifying the compounds is by using 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.