Master of Engineering Science
Chemical and Biochemical Engineering
Dr. Mita Ray and Dr. Lars Rehmann
Solid phase extraction (SPE) using chemically bonded silica particles or small particles of an organic polymer resin, is being studied extensively for extraction of polar or non-polar compounds from various water matrices. This study focused on the evaluation of the performance of three commercial cartridges belonging to three different groups: reversed-phase, mixed-mode anion exchanger and mixed-mode cation exchanger. In the first stage of research, the performance of three cartridges was compared by extracting four antibiotics with different physic-chemical properties from water samples. The results obtained from column sorption experiments were plotted into breakthrough curves and batch equilibrium experiments results were fitted into Langmuir and Freundlich isotherms. Based on the parameters obtained from these plots, Oasis MCX was determined to be the best cartridges of the three for various analyte extractions. The recovery efficiency of each cartridge was studied by eluting the sorbent with acetone. The recovery of LC-18 sorbent was between 72% ~ 104% depending on the compounds, while both Oasis MAX and MCX cartridge can achieve approximately 100% recoveries.
In the second stage of the study two bioassays and HPLC analysis were used to evaluate the influence of different background water matrices on the performance of the SPE sorbents to extract known amount of estradiol from surface water and wastewater samples. Finally the quality of surface water and wastewater was examined in Ames assay and YES assay with samples pre-concentrated by Oasis MCX cartridge. No mutagenicity (determined by the Ames assay) and estrogenicity (determined by YES assay) were found in the raw water samples and SPE treated samples. With the assistance of bioassays and HPLC analysis, it was demonstrated that surface water has a minor influence on the recovery of Oasis MCX sorbent. However, the recovery of MCX sorbent decreased to 84.65% when wastewater was used as the background matrix. The work determined that Oasis MCX was the ideal sorbent for sample extraction in different water matrices.
Feng, Chen, "Solid-phase Extraction as Sample Preparation for Bioassay-based Micropollutant Quantification" (2014). Electronic Thesis and Dissertation Repository. 2363.