Ion trap mass spectrometry for the performance based analytical methods: Strategies for the method improvements of SVOC monitoring in environmental samples.

摘要

An introductory (chapter I) describes the basic principles of ion trap mass spectrometry (ITMS) and its great potential as an analytical detection tool for performance based analytical methods, which are designed to identify and quantify a number of semi-volatile organic compound (SVOC) pollutants at extremely low levels of analyte simultaneously. Applications of ITMS and strategies for method improvements of SVOC monitoring in environmental sample analysis were introduced. Chapter I also suggests a hypothesis that increasing ionization time manually in ITMS could bring about more sensitivity than controlling ionization time automatically by the manufacture's supplied software.;In chapter II, this hypothesis was tested using two different ITMS systems, which consisted of a GC/electron impact (EI)-ITMS system with an internal ionization source (within the trap) and an HPLC/electrospray (ESI)-ITMS system with an external ionization source (outside of the trap). The results from two separate experiments concluded nearly identically that manual tuning of ionization time could bring 3 to 5 times more signal intensity than computerized automatic tuning without sacrificing spectral quality. The optimization approaches to achieve better sensitivity and mass spectral quality using various parameters that affect GC/electron impact (EI) or HPLC/electrospray (ESI) ITMS operation are also discussed in chapter II. Two parameters, other than ionization time in the GC/EI-ITMS system include; optimization of filament emission current and ion trap temperature.;Chapter III described a simultaneous method for determination of SVOCs in drinking water sources using solid-phase extraction (SPE) followed by temperature programmed large volume injection into a capillary column GC using both EI-ITMS and chemical ionization (CI)-ITMS. A continuous flow (CF)-SPE was developed and optimized to treat multiple large volume (1--5 liters) water samples simultaneously.;An improved microwave assisted solvent extraction (MASE) method to screen more complex matrixes, such as soil, dust or sediment for U.S. EPA SVOC pollutants, was introduced and studied in the chapter IV.;In chapter V, advanced ITMS detection strategies were investigated to deal with complex mixture analysis, where trace amounts of analyte should be identified and quantified in the presence of complex matrix interferences. (Abstract shortened by UMI.).