DEVELOPMENT OF MICROEXTRACTION TOOLS COMPATIBLE WITH THERMAL AND SOLVENT DESORPTIONS SUITABLE FOR TARGETED AND UNTARGETED ANALYSIS

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2023-1-25

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Kahremanoğlu, Kübra

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Solid phase microextraction (SPME) is one of the essential tools present in the analytical toolbox integrating the sampling and sample preparation into a single step. Because of this unique feature, SPME is distinct among other technologies as a tool suitable for in-vivo, on-site, and in-vitro applications. Up to date, a plethora of extractive phases suitable for targeted and untargeted studies have been developed for SPME. However, usually, they are only suitable for solvent or thermal desorption followed by liquid/gas chromatographic separation. This limits the applicability of the device for untargeted analysis where a system-representative chemical snapshot is needed. Therefore, the development of extractive tools and methods that can be used both with solvent and thermal desorption, providing wide-range analyte coverage is of great importance. In this study, hydrophilic-lipophilic balanced particles providing wide-range analyte coverage were immobilized in the polyfluorinated amorphous polymer (PTFE-AF 2400) to have SPME devices that are biocompatible, with sufficient solvent and thermal stability. SPME devices with different geometries were prepared, optimized, and used in two different applications. The first type of device was a miniaturized SPME probe that is suitable for metabolomic, and pharmacokinetic profiling in cell cultures, and tissues where a spatial resolution of chemical information is crucial. It was shown that the developed SPME-LC-MS method using HLB/PTFE AF microprobes, enables the extraction of wide range of molecules (Log P varies between -4.2 and 15.6) with acceptable method accuracy and repeatability. The second type of device was thin film SPME, capable of more sensitive analysis due to its larger surface area and on-site sampling. Using these thin film devices, a TFME-GC-MS method was developed for the determination of pesticides in apple juice. The developed TFME-GC-MS method is accurate and repeatable for the determination selected pesticides (except trifluralin at high-point concentration, 300.0 ng/mL). Preliminary studies also had shown that samplers are suitable for on-site sampling.

Subject Keywords

solid phase microextraction, thin film microextraction, metabolomics, mass spectrometry, biocompatible materials

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https://hdl.handle.net/11511/102545

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

K. Kahremanoğlu, “DEVELOPMENT OF MICROEXTRACTION TOOLS COMPATIBLE WITH THERMAL AND SOLVENT DESORPTIONS SUITABLE FOR TARGETED AND UNTARGETED ANALYSIS,” M.S. - Master of Science, Middle East Technical University, 2023.