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The second half of the twentieth century has seen the dawn of the environmental movement. Along with our technological and scientific awareness, has come the realization that our efforts to improve our human condition have caused damage to our environment. In this age of developing environmental enlightenment, one task of analytical chemists has been to assist in the detection and identification of many environmental pollutants. Environmental measurements often involve separation of the analyte from the matrix. Chromatographic separations, especially those involving a gaseous mobile phase (GC), have been widely used. The separation itself does not measure the analyte, however, and chromatographic separation is usually followed with some detection method. One of these methods involves the use of a microwave plasma to break down the analyte into its elemental components and excite those elements with energy such that they emit specific wavelengths of light. Those wavelengths can then be monitored to measure the analyte. The following work describes the use of such a detector, known as an atomic emission detector (AED), for the detection of several pollutants. First, the AED has been implemented for the detection of fluorine and oxygen simultaneously. This is important for the determination of fluoroethers, thought to be a replacement for ozone layer destroying chlorofluorocarbons. Under normal plasma conditions, fluorine etches the tube used to contain the plasma and results in an oxygen response regardless of whether the compound contains oxygen or not. A new plasma was evaluated that uses carbon to protect the walls of the tube from etching and thus greatly reduces the spurious oxygen response. Detection limit and linear dynamic range data is presented. Second, a method was evaluated for the calibration of plasma response with alternative calibrants. Chlorpyrifos was used to calibrate AED response for triademifon, isazofos, and trichlorfon. It was determined that calibration could only be obtained for the isazofos, there being a statistically significant difference between calibration of the chlorpyrifos and the other pesticides. Methods of using large injection volumes with cool-on-column injection was developed to eliminate the need for preconcentration of pesticide samples. Triademifon, isazofos, and trichlorfon were successfully determined at trace levels with no degradation of the chromatographic performance due to the large injection volumes. A method of thermal extraction of priority pollutants was developed. Chlorpyrifos was thermally extracted from soil samples. However, the pesticide showed extraction recoveries that were dependent on the age of the sample. That made calibration of the method impossible. Polychlorinated biphenyls (PCBs) were also used in the evaluation. These showed no time dependence and therefore calibration of the method was possible. Levels of PCBs in a standard reference material (SRM) were determined and compared to certified values. Finally, 1,1,1-trifluoroethyl hydrazine (TFH) was used to derivatize aldehydes for their determination by GC-AED. Good recoveries were obtained. In the determination of aldehydes in ozonated waters, however, the detection limit was found to be much higher than those of competing techniques.

The kinetic nature of flow injection (FI) experiments has led to the development of analytical methods that rely on the concentration gradients that are formed as a result of the hydrodynamics of the flowing stream. The concentration-time profile of the flow injection peak contains a wealth of chemical information, most of which are ignored in the typical FI experiment based on peak height. The objective of this work was to study a number of novel ways in which concentration-time data obtained from a variety of FI experiments can be used for analytical determinations and for the determination of fundamental reaction parameters. Time intervals were used as quantitative analytical parameters for slow and fast reactions. The Belousov-Zhabotinskii oscillating chemical reaction was generated in a flow injection system and monitored under conditions of stopped flow. The injection of an analyte into the slowly reacting system altered the behavior of the reaction. Times between events on the absorbance-time profile were used in a new kinetic method of analysis. The time interval between doublet peaks was the analytical parameter used in a study of FI doublet peaks. Mixing devices used in the experiment were compared and various aspects of the theory behind flow injection peak-width methods were discussed. Results from FI doublet peak determinations were presented and the overall precision of the method was evaluated. Formation quotients and reaction rate constants were calculated from sets of data points taken from the concentration-time profile of the FI peak. A flow injection system incorporating a well-stirred tank was used to create the concentration gradients from which the data were obtained. Two iterative methods were used to calculate formation quotients from absorbance-time data. The well-stirred tank model was modified for the situation of removal of sample by reaction. Novel ways to determine rate constants from absorbance-time data were based on the derived equations.