The isolation and identification of pheromones at the microgram level requires specialized techniques. The pheromones are obtained in the purity required for structural studies by high-speed, high-pressure liquid chromatography using silicic acid- and silver nitrate-treated columns and micropreparative GLC. Then, microchemical reactions, including hydrogenation, ozonolysis, and epoxidation are combined with infrared, nuclear magnetic resonance, and mass spectral studies to elucidate the structure of these compounds. In many cases these techniques are synergistic when combined. Thus, samples of 5-10 μg of most organic compounds under molecular weight 350 are sufficient for complete structural elucidation by using microchemical and spectroscopic techniques. The reduction in sample (2 μg) size necessary for good PMR spectra is significant because the information provided by this technique is often critical to the elucidation of a structure, and sensitivity of PMR has been one of the limiting factors in microspectroscopic analysis.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics