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cap alpha..-cyclodextrin-induced solid-surface room-temperature luminescence (CISS-RTL) was used to characterize synthetic mixtures of polynuclear aromatic hydrocarbons (PAH) adsorbed on ..cap alpha..-cyclodextrin-sodium chloride mixtures. With CISS-RTL, qualitative analysis of binary mixtures of benzo(a)pyrene and benzo(e)pyrene was easily accomplished even at nanogram levels. In addition, a technique was also developed that was used in characterizing a nine-component PAH mixture. This method employs extraction, selective excitation, and detection by CISS-RTL and solution fluorescence spectroscopy. Nine PAH of various sizes ranging from a two-ring compound (naphthalene) to a ten-ring compound (decacyclene) were selected as model compounds, and several synthetic mixtures containing different amounts of the nine PAH were prepared and were analyzed by this approach. The results showed that between seven to nine PAH were identified in the mixtures at nanogram levels.

Several polymer-salt mixtures were examined as solid surfaces for room-temperature phosphorescence (RTP). A variety of hydroxyl-substituted aromatic compounds were observed to give RTP when absorbed on poly(acrylic acid) (PAA)-sodium halide mixtures and filter paper. A solid-sample holding plate was used with a spectrodensitometer for solid surface luminescence detection of components on powder and filter paper adsorbents. RTP analytical data, including linear ranges of calibration curves and limits of detection for several compounds, were compared for 1% PAA-NaBr powder and filter paper.

Room-temperature fluorescence and phosphorescence quantum yield, triplet formation efficiency, and phosphorescence lifetime values were obtained for the anion of rho-aminobenzoic acid adsorbed on sodium acetate and several sodium acetate-sodium chloride mixtures. From these data, rate constants for phosphorescence and for radiationless transition from the triplet state were obtained. The results revealed that several factors are important for maximum room-temperature phosphorescence for the anion of rho-aminobenzoic acid. One of the most important conditions for strong room-temperature phosphorescence of the anion was how efficiently the matrix was packed with sodium acetate molecules. The same general conclusion was found for room-temperature fluorescence, but the phosphorescence quantum yield increased more dramatically than the fluorescence quantum yield.

The interactions of ..cap alpha..-cyclodextrin-analyte responsible for the luminescence phenomenon observed from compounds adsorbed on an 80% ..cap alpha..-cyclodextrin-sodium chloride mixture were compared with the interactions of the prepared solid-phase ..cap alpha..-cyclodextrin complexes of the compounds. Diffuse reflectance spectrometry and luminescence spectrometry were used in the study. The luminescence data with benzo(f)quinoline (B(f)Q) indicated that the nitrogen-containing ring of B(f)Q was inside the ..cap alpha..-cyclodextrin cavity in the 80% mixture, while in the prepared inclusion compound the pyridinic nitrogen was outside the ..cap alpha..-cyclodextrin cavity. The diffuse reflectance spectra of several compounds adsorbed on an 80% ..cap alpha..-cyclodextrin-sodium chloride mixture and on NaCl were compared. Some of the compounds showed a red shift in their reflectance band maximum, and other compounds showed well-resolved vibronic bands on the 80% ..cap alpha..-cyclodextrin mixture. In addition, the amount of unbound analyte on the ..cap alpha..-cyclodextrin-sodium chloride matrix was determined.

A single luminescence method is described in which second derivative solid surface phosphorescence and fluorescence were used for the qualitative analysis of two components in high-performance liquid chromatography (HPLC) fractions. The method was applicable to solvents from both normal and reversed-phase HPLC systems. The approach demonstrates how fluorescence and phosphorescence can be combined at room temperature for qualitative analysis. 5 references, 6 figures.

Several spectral techniques were used to study the interactions of hydroxyl aromatics and aromatic hydrocarbons with poly(acrylic acid)-salt mixtures and filter paper. The results revealed hydrogen bonding of the model hydroxyl aromatics and aromatic hydrocarbons to the support materials. The individual phosphors acted as hydrogen donors, hydrogen accepting species, or as both hydrogen donors and hydrogen acceptors. Infrared data showed a net increase or decrease in the inter- and intramolecular hydrogen bonding network of the solid supports with the addition of phosphors, suggesting specific geometric requirements for adsorption of the phosphor. Diffuse reflectance spectra and luminescence emission spectra indicated that room-temperature phosphorescence was emitted by the neutral hydroxyl aromatics adsorbed on the solid surfaces. 23 references, 3 figures, 4 tables.

Several experimental parameters were studied to enhance the room-temperature phosphorescence of nitrogen heterocycles adsorbed on polyacrylic acid-salt mixtures and filter paper. The room-temperature phosphorescence was very sensitive to the salt content of the solid surface and the solvent used to adsorb the phosphor onto the surface. Sodium chloride and methanol were particularly important for inducing strong room-temperature phosphorescence. The results obtained partially explain some of the interactions responsible for room-temperature phosphorescence from nitrogen heterocycles. 2 figures, 5 tables.

The room-temperature fluorescence (RTF) and room-temperature phosphorescence (RTP) intensities of benzo(f)quinoline (B(f)Q) and phenanthrene were obtained from several ..cap alpha..-cyclodextrin-sodium chloride mixtures. The results showed the importance of the initial wet chemistry in the sample preparation procedures for the observation of luminescence signal for compounds adsorbed on ..cap alpha..-cyclodextrin-sodium chloride mixtures. The data indicated that in order to obtain the optimum RTP and RTF signals, the solvent used to adsorb the analytes had to be saturated with ..cap alpha..-cyclodextrin. Also, the solid-surface fluorescence and phosphorescence quantum yield, triplet formation efficiency, and phosphorescence lifetime values were obtained for B(f)Q and phenanthrene adsorbed on 0.05% and 80% ..cap alpha..-cyclodextrin-sodium chloride mixtures. From these data, rate constants for phosphorescence and for radiationless transition from the triplet state were obtained.

The room-temperature fluorescence (RTF) and room-temperature phosphorescence (RTP) of benzo(f)quinoline and benzo(h)quinoline, obtained from the samples adsorbed on silica gel chromatoplates submerged in chloroform/n-hexane solvents, revealed several of the interactions of the nitrogen heterocycles with the solid matrix. The RTP results showed the emitting phosphor was protected from collisional deactivation by the matrix and that the adsorbed chloroform minimally disrupted the phosphor adsorption interactions. In addition, at least two populations of phosphors were indicated. The RTF data and RTP data showed that different interactions were occurring in the singlet state compared to the triplet state. A comparison of RTF intensity and TRP intensity as a function of chromatographic solvent strength indicated that the protonated forms of the nitrogen heterocycles in their triplet states were interacting with the matrix more strongly than the protonated forms of the nitrogen heterocycles in their singlet states.

Recent research activity in the area of luminescence from compounds adsorbed on solid supports has centered around the development of room-temperature phosphorescence (RTP) as an analytical technique. Much of this work is summarized in recent reviews. Filter paper has been the most widely used adsorbent for inducing RTP from aromatic molecules. In addition, considerable work has been reported on room-temperature fluorescence (RTF) analysis of organic compounds adsorbed on solid surfaces. However, there has been only one report of the combined use of solid-surface RTF and RTP for qualitative analysis. One limitation in the use of solid surface RTP and RTF for qualitative analysis arises from the fact that the spectra usually have broad bands. For this reason, the identification of individual compounds by examination of the luminescence spectra from a mixture can sometimes be difficult. This is especially true for compounds whose spectra overlap extensively. In this study, the combined information of RTP excitation and emission and RTF emission spectra was used for qualitative analysis. Both zeroth and second derviative RTP and RTF spectrometry were used in the work.

Room-temperature phosphorescence (RTP) has generated considerable interest over the past several years. Several materials have been used to induce RTP from a variety of compounds. However, there is still a need to test additional materials and experimental conditions for RTP so the maximum sensitivity and selectivity can be obtained. In this work, three solid surfaces and several experimental conditions were tested for RTP of nitrogen heterocycles and aromatic amines. Nitrogen heterocycles and aromatic amines are an important class of compounds as shown by work in areas such as environmental research and coal liquefaction research. 18 references.

A method was developed for identifying and determining benzo(a)pyrene in a filtered retort water sample from an in situ oil shale process by employing liquid-liquid extraction, dry-column chromatography, thin-layer chromatography and fluorescence spectrometry. The accuracy and precision of the method were good, and the limit of detection was approximately 0.08 ppB. Irreproducible results were obtained with unfiltered retort water samples. Programmed multiple development was used to a limited extent in the separation of polycyclic aromatic hydrocarbons from a shale oil sample. However, results indicated that this separation technique should be investigated further in the separation of polycyclic aromatic hydrocarbons. Benzo(a)pyrene was determined in several shale oil samples by methods developed previously. Polycyclic aromatic hydrocarbons were characterized in several shale oil samples using open-column, dry-column and thin-layer chromatography as separation steps. Visible fluorescence from the separated components on chromatoplates was measured directly to obtain fluorescence profiles of the components on the chromatoplates. Several comparisons were made among the shale oil samples as to the relative amounts of 6-, 5-, 4- and 3-ring polycyclic aromatic hydrocarbons. The theoretical and practical analytical aspects of the room temperature phosphorescence of nitrogen heterocycles were investigated. Intense room temperature phosphorescence was obtained from several nitrogen heterocyclesmore » when these compounds were absorbed on silica gel. Theoretical explanations were given for the intense phosphorescence. Benzo(f)quinoline and phenanthridine were separated from a shale oil sample by open-column and high performance liquid chromatography, and then identified by room temperature phosphorescence.« less