Solid Phase Microextraction in Aqueous Sample Analysis

Abstract

This thesis presents enhanced analytical methods developed for complex aqueous sample analysis based on solid phase microextraction (SPME). First, the laboratory evaluation of the kinetic calibration approach in aqueous sample analysis using SPME is discussed. A modified SPME device, Polydimethylsiloxane (PDMS) rod passive sampler, was developed and the kinetic calibration method based on the standard preloaded in the extraction phase was applied to determine the time-weighted average (TWA) concentration of organic pollutants in water. Later, the SPME technique was used to investigate the complex interactions between the organic pollutants and humic organic matter (HOM) present in the aqueous samples. The kinetics of the SPME approach in complex aqueous samples was studied. The concentration of freely dissolved analytes and the total concentration of the target analytes in the sample matrix were determined by SPME sampling. The usefulness of the SPME approach for binding studies was further demonstrated by determining the sorption coefficient, a useful parameter for studying the bioavailability of the organic pollutants in the environment. In addition, the commercial Computational Fluid Dynamics (CFD) software COMSOL Multiphysics was used to predict the kinetics of analyte extraction and flow pattern under different experimental conditions using the SPME technique. A good agreement between the prediction and the experimental data confirms the advantages of the CFD application for experimental optimization thus minimizing the need of extensive experiments.