Development and application of solvent-minimized extraction technologies

Abstract

Sample preparation plays an essential role in an analytical procedure and is receiving increasing attention in the past few decades. Solvent-minimized extraction (Microextraction) methods have established an important trend in sample preparation and undergone rapid development. This thesis describes the development of several novel microextraction techniques and their applicability in environmental sample analysis. Firstly, two new solvent bar microextraction (SBME), SBME combined with simultaneous derivatization for pharmaceutically active compounds and ionic liquid supported three-phase liquid-liquid-liquid SBME for phenols, were developed. Secondly, three novel dispersive liquid-liquid microextraction (DLLME) techniques, including low-density solvent based ultrasound-assisted emulsification microextraction (LDS-USAEME) combined with on-column derivatization, electro membrane extraction coupled to LDS-USAEME, and low-density solvent-based solvent demulsification DLLME, were developed for various analytes. Lastly, multiwalled carbon nanotubes based micro-solid-phase extraction (?-SPE) was developed for determining polycyclic aromatic hydrocarbons. The proposed approaches in this thesis extend the applicability and open new ways for LPME and ?-SPE.