Room-temperature Phosphorescence RTP

Phosphorescence is usually not observable in fluid solution even from compounds with high triplet yields, being overruled by nonradiative triplet deactivation and/or quenching by co-solutes such as O2. Cyclodextrin indusion is a way to overcome 

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The aim of this work is the development of pyrene determination in gasoline and contaminated soils. For this purpose we used room temperature phosphorescence (RTP) in micellar solutions of sodium dodecylsulphate (SDS). For pyrene extraction from contaminated soils hexane was used. Then exttacts earned in glass and dried. After that remains was dissolved in SDS solution in the presence of sodium sulphite as deoxygenation agent and thallium (I) nitrate as heavy atom . For pyrene RTP excitation 337 nm wavelength was used. To check the accuracy of the procedures proposed for pyrene determining by RTP, the pyrene concentrations in the same gasoline samples were also measured by GC-MS. 

Room-temperature phosphorescence (RTP), dispersing the compound under investigation in a transparent polymer matrix such as Perspex... 

In some cases, room temperature phosphorescence (RTP) may be achieved in the absence of a well-defined ternary complex. A heavy atom substituent on... 

A number of less commonly used analytical techniques are available for determining PAHs. These include synchronous luminescence spectroscopy (SLS), resonant (R)/nonresonant (NR)-synchronous scan luminescence (SSL) spectrometry, room temperature phosphorescence (RTP), ultraviolet-resonance Raman spectroscopy (UV-RRS), x-ray excited optical luminescence spectroscopy (XEOL), laser-induced molecular fluorescence (LIMP), supersonic jet/laser induced fluorescence (SSJ/LIF), low- temperature fluorescence spectroscopy (LTFS), high-resolution low-temperature spectrofluorometry, low-temperature molecular luminescence spectrometry (LT-MLS), and supersonic jet spectroscopy/capillary supercritical fluid chromatography (SJS/SFC) Asher 1984 Garrigues and Ewald 1987 Goates et al. 1989 Jones et al. 1988 Lai et al. 1990 Lamotte et al. 1985 Lin et al. 1991 Popl et al. 1975 Richardson and Ando 1977 Saber et al. 1991 Vo-Dinh et al. 1984 Vo- Dinh and Abbott 1984 Vo-Dinh 1981 Woo et al. 1980). More recent methods for the determination of PAHs in environmental samples include GC-MS with stable isotope dilution calibration (Bushby et al. 1993), capillary electrophoresis with UV-laser excited fluorescence detection (Nie et al. 1993), and laser desorption laser photoionization time-of-flight mass spectrometry of direct determination of PAH in solid waste matrices (Dale et al. 1993). 

Materials and apparatus. The 2-bromoquinoline-3-boronic acid (BrQBA) (97%), D-glucose (99%) and D-mannose (99%) were purchased from Alfa Aesar. NaDC (+99%), D-fructose (99%) and D-galactose (99%) are products of Acros Organics. A Cary Eclipse luminescence spectrometer (Varian Company) was employed to obtain room temperature phosphorescence (RTP) spectra and measure lifetime. 

Room temperature phosphorescence (RTP) spectrum and lifetime of BrQBA in NaDC. BrQBA gave a weak fluorescence and no phosphorescence in aqueous solution because of the quenching by dissolved oxygen. However, a strong RTP signal was observed in a NaDC solution without any deoxygenation, with emission at 500 nm. 

The room-temperature phosphorescence (RTP) of benzo[/]quinoline and phen-anthridine shows enhancement by spotting HBr-ethanol solutions of the compounds onto silica gel chromatographic plates, Acridine however showed no RTP emission but gave strong fluorescence. Possible interaction effects of the compounds with the substrate are discussed. 

Phosphorescence is also enhanced when luminophores are included in the cyclodextrin cavity. This room temperature phosphorescence (RTP) proved itself to be a useful analytical technique. In conventional liquid media, polycyclic aromatic hydrocarbons (PAHs) do not show any appreciable phosphorescence, especially at room temperature. However, when a stable ternary complex is formed with the aromatic compound, /S-cyclodextrin, and an intersystem crossing promoter such as 1,2-dibromoethane, intense phosphorescence is observed. ... 

The phosphorescence spectra ofbenzophenone (BP) were studied in the TMOS sol-gel systems at 77 K (Matsui, 1999). The phosphorescence spectra were ascribed to solvent-free BP, aggregated BP, and a BP-water complex in these systems. The spectra vary with the BP concentration and the sol-gel conditions such as the water/TMOS ratios, catalyst, and the various sol-gel reaction stages. In general, phosphorescence is observed at low temperature as above. However, room temperature phosphorescence (RTP) was obtained... 

Phosphorescence can also be detected when the phosphor is incorporated into an ionic micelle. Deoxygenation is still required either by degassing with nitrogen or by the addition of sodium sulphite. Micellestabilized room-temperature phosphorescence (MS RTP) promises to be a useful analytical tool for determining a wide variety of compounds such as pesticides and polyaromatic hydrocarbons. 

Because of the long radiative lifetime of the lowest triplet state, most phosphorescence in fluid solutions is obviated by collisional quenching, especially by dissolved molecular oxygen. Phosphorescence, when it occurs, is usually observed at low temperatures (e.g., that of liquid nitrogen) in rigid matrices where it may demonstrate high quantum yields. In the past three decades, much interest has been focused on phosphorescence at room temperature (RTP), which sometimes can be observed in samples adsorbed on solid substrates such as filter paper. Unfortunately, the quantum yields observed in room temperature phosphorescence are low, leading to poor analytical sensitivity, and the method has not enjoyed wide popularity. Phosphorescent measurements at low temperatures... 

Most of the sections of this book discuss the photophysical processes following absorption of electromagnetic radiation, therefore, a very concise review of the terms and concepts relevant to triplet states and phosphorescence is given at the beginning of this chapter. Then the quenching and protection of triplet states and phosphorescence and heavy atom effects are introduced briefly. The typical systems and methodologies on inclusion complex, and typical applications of CD induced-room temperature phosphorescence (CD-RTP) are then discussed. Finally, some important conclusions are made. 

Metal-ion MS-RTP determinations have also been demonstrated. For example, platinum(II) chelates with 8-quinolinol derivatives were found to form highly phosphorescent complexes at room temperature in the sugar-based -dodecyl-/l-D-maltoside micellar medium, using iodine as heavy atom (see Figure 2). 

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