Chromatographische Untersuchungen und Extraktion von Pyrethrinen und Pyrethroiden

In this study chromatographic methods to analyze pyrethrins and pyrethroids are developed. Different extraction methods for sample preparation are applied.
Chromatographic separation of the insecticide active substances is done by both supercritical fluid chromatography (SFC) with positive pressure gradient, and high performance liquid chromatography (HPLC). The exact elution order in SFC is determined with SFC-MS-coupling. The content of pyrethrins and the content
of every single pesticide is established with flame ionization detection (FID) and carbon calibration. The pyrethroide allethrin is used as reference substance. Carbon calibration is applied for selected synthetic pyrethroids.
The six natural insecticides in pyrethrum are separated by HPLC with a linear elution gradient and UV-detection. Different extraction methods for solid sample preparation are investigated. Ultrasonic-, Soxhlet-, accelerated solvent- and supercritical fluid extraction are compared with regard to their maximal extraction of insecticides. Fractional factorial design was used to optimize selective extraction of pyrethrins by SFE.