Microextraction with solid-matrix luminescence and the effects of moisture on solid-matrix luminescence

The initial part of this research involved the use of partially hydrophobic filter paper as a medium for solid-phase microextraction of polycyclic aromatic hydrocarbons (PAH) and as a matrix for detection of PAH using solid-matrix fluorescence (SMF) and solid-matrix phosphorescence (SMP). With 1PS paper, it was possible to extract and identify PAH in mixtures containing up to four components. Also, mass balance data for the extractions were acquired. Effective partition coefficients were calculated using an equation that assumed that the solutes did not interact with the stir bar or vial wall of the extraction system. Another equation was used that did make these assumptions. Many of the solutes adsorbed on the magnetic stir bar and glass vial, but both equations reflected the trends in the effective partition coefficients among the solutes investigated.; The effects of moisture on SMF and SMP quenching were also studied. Significant SMP matrix quenching was observed for all phosphors with increasing moisture content. On No. 1 and 1PS papers, SMP diffusional quenching was not observed for phenanthrene and benzo[e]pyrene, even though the SMP lifetimes were in the one-second range. However, diffusional quenching of perdeuterated phenanthrene occurred on both papers. This compound had a SMP lifetime of approximately 5 s. Several equations were developed to explain the SMP quenching phenomena. The quenching of SMP on filter paper was also studied as a function of time of exposure to moisture. At 10% relative humidity on both papers, a portion of the SMP signal remained even after exposure for 1h. At 40% relative humidity, the SMP on No. 1 paper was completely quenched after 30 min, and at 20% relative humidity the SMP on 1PS paper was completely quenched after 1 h of exposure.; To improve the extraction efficiency of hydrophobic paper, two methods were developed to coat No. 1 filter paper using dichlorodimethylsilane and Dow-Corning Silicone 1107. Also, infrared spectrometry was used to characterize the coated papers. The coated papers gave limits of detection and effective partition coefficients superior to those obtained with 1PS paper. However, the silicone-coated paper was a better etraction matrix than the silane-treated paper.