Direct On-Line Continuous Supercritical Fluid Extraction and HPLC of Aqueous Pyrethrins Solutions

Abstract

A new method, employing supercritical fluid extraction (SFE) connected on-line with high-performance liquid chromatography, was developed for the determination of pyrethrins and piperonyl butoxide in aqueous solutions. The principle of the laboratory-made device for SFE is based on the low mutual solubility of water and supercritical (liquid) CO2. This device works in continuous mode that offers extraction of unlimited sample volumes. Different extraction temperatures and pressures were tested to find optimum extraction conditions. The addition of organic modifier and inorganic salt to the water sample to increase extraction recovery was investigated. The method was evaluated, and it was applied for the extraction of aqueous samples spiked with commercial insecticides. The working concentration range of the method was from the limit of quantification (0.1 microg L(-1)) to the solubility of the analytes in water.

Fast GC×GC with Short Primary Columns

“…As a demonstration, the technique is applied to the separation of natural pyrethrin compounds in Chrysanthemum cineraefolium extract. The natural pyrethrins are a family of six compounds extracted from chrysanthemum flowers and are valuable insecticides, especially for organic farmers, as their use is permitted in organic agriculture. , For the purpose of demonstration of this novel GC×GC approach, these analytes are useful due to the fact that they are thermally labile, degrading at temperatures over 200 °C. , Additionally, when extracted from chrysanthemum flowers, they are present in a reasonably complex matrix that can have numerous coeluents and present a challenge to the analyst where resolution of all components is required.…”

Sustainable approaches for the study of alkaloids from plants using supercritical fluid-based processes

“…139 In the agroindustry, insecticides extracted from flowers such as pyrethrins were analyzed by the on-line SFE-HPLC strategy, yielding adequate resolution and recoveries of >78.4%. 140 This is a good alternative since pyrethrins degrade at temperatures above 200 °C and GC, the most used analytical technique for insecticide detection, is not suitable for this purpose. Derivatization of these compounds before GC analysis is a solution to this problem but is an extra step in the analytical process.…”

Supercritical Fluid Extraction - New progressive method in brewing analytics. Part I. - Theoretical principles of supercritical fluid extraction and examples of its use.

“…Barnabas et al [22] used SFE similarly to extract organochlorine derivates. SFE combined with HPLC detection is also establishing itself in the analysis of pesticides [23,24]. Furthermore, the anabolic content in water and blood plasma was determined with the help of this method [25,26].…”