| Analysis of volatile organic compounds (VOCs) is an important analytical task because of the prevalence of these compounds and the detriment they pose to the environment and human health. There are many improvements that are possible in the extraction and detection steps of these analytes. This dissertation will focus on these improvements. In particular, an extraction apparatus was developed in our laboratory for the removal of VOCs from aqueous samples in less than one minute. Also, a detector that is highly selective for aromatic VOCs will be discussed in detail.;Extraction of VOCs from aqueous samples into the gas phase is often the time-limiting step in an analysis. A rapid aqueous sample extraction (RASE) system was developed that was capable of extracting a VOC from water in less than 15 seconds. It may be coupled on-line with cryofocussing high speed gas chromatography (HSGC) with flame ionization detection (FID). This system was capable of separating five analytes in 10--15 seconds. The sensitivity was in the low mug/L range for analytes such as cyclohexane, toluene, o-xylene, and isopropylbenzene. An advantage of interfacing these systems was that they were capable of handling mixtures that contain complex matrices, such as wastewater. A wastewater sample spiked with cyclohexane, toluene, o-xylene, and isopropylbenzene was extracted, separated and detected with the RASE/HSGC system in less than 45 seconds.;The aromatic specific laser ionization detector (ArSLID) was a highly selective and sensitive alternative for the detection of aromatic VOCs. It operated using resonance enhanced multiphoton ionization (REMPI) and studies were conducted at atmospheric pressure using a low-cost microlaser. At 266.0 nm, the ArSLID was highly selective for a variety of aromatic VOCs. Experiments to determine the sensitivity and selectivity of the ArSLID were demonstrated using gas samples containing 0.1 mug/L (1 pg) each of benzene, toluene, ethylbenzene, o-xylene, and isopropylbenzene, which were separated in less than 30 seconds. These samples also contained non-aromatic compounds that were not detected because their ionization potentials were greater than those of the analytes studied. The ArSLID provided improved selectivity compared to the photoionization detector (PID) or the FID. |
