Samenvatting

This graduation report describes a research project at the research group metabolomics of the Leiden center of Applied Biosciences (LCAB). The aim of this project was to develop a GC-MS method for the identification of red swamp crayfish pheromones (Procambarus clarkii). Once this method has been developed, it can be used to monitor a population of crayfish by analyzing water samples. This is much less labour-intensive compared to the current method: the manual capture and registration of the crayfish.
Biogenic amines were expected to be potential pheromones of the crayfish. For this reason the method was developed on the basis of a mixing standard consisting of eight amino acids octopamine and serotonin. Water samples were processed with the Waters MCX SPE column. After solid phase extraction, the samples were derivatized with MTBSTFA and as catalyst pyridine. All samples were analyzed on the GC-MS. The NIST database was used to identify the analytes.
During the method development the split ratio of the GC injection and the recovery percentage of the SPE procedure were optimized. After optimization, the reproducibility and the detection limits of the analytical method were determined. Finally a selection of water samples were analyzed obtained from previously performed laboratory experiments with crayfish in aquaria.
The results show that the analytical method is capable of identifying biogenic amines in water samples. However no pheromones specific for the red American crayfish were identified. It was concluded that the detection limits of the method for the pheromones are too high. As a result, the analytical method is not yet able to monitor a population of crayfish.