Environmental analysis based on luminescence in organized supramolecular systems

Abstract

The use of organized supramolecular systems-including micellar media and cyclodextrin inclusion complexes-combined with luminescence techniques in the study and determination of compounds and elements of environmental interest from 1990 to 2005 is reviewed. Analyses of environmental samples performed using fluorescence, photochemically induced fluorescence and phosphorescence spectroscopy as well as liquid chromatography, capillary electrophoresis and flow injection with luminescence detection in the presence of these organized media are described in detail.

Luminescence methods for study and determination of pollutants in the environment

“…In addition, several organized media, including micelles and cyclodextrins, have been extensively applied to luminescence methods and other related analytical techniques, and have generally permitted to enhance their sensitivity and selectivity [15][16][17][18][19][20][21][22][23][24]. On the one hand, micelles are prepared by adding appropriate amounts of surfac-tants in water or water-organic mixtures.…”

“…The surfactant molecules will aggregate in aqueous or partially-aqueous solution to form micelles of a colloidal size, when the surfactant concentration exceeds a certain threshold value, called critical micelle concentration (CMC), at temperature higher than its Kraft temperature [25]. By using micellar media, it is possible to modify the solubility and microenvironment of analytes, and to increase their luminescence signal [24]. On the other hand, cyclodextrins (CDs) are water-soluble, cyclic oligosaccharides, and, depending on their size, they can form inclusion complexes with appropriate organic molecules, producing changes in their photophysical properties.…”

Simultaneous determination of 9-ethylphenanthrene, pyrene and 1-hydroxypyrene in an aqueous solution by synchronous fluorimetry using the double scans method and hydroxyl-propyl beta-cyclodextrin as a sensitizer

“…HPCD deserves special attention due to its higher aqueous solubility, lower toxicity and more hydrophobic cavity compared to the parent compound, making it a good choice for incorporation of lipophilic molecules into the CD cavity [21]. Therefore, the introduction of CDs enabled us to improve analytical measurements, eliminate or reduce solubility issues with organic compounds, augment the sensitivity and precision, and increase the selectivity of the analytical method [22]. More importantly, studies on the bioavailability and toxicity of PAHs could address the restrictions on the solubility limit by introducing CDs [23].…”

Determination of the fenvalerate insecticide in natural waters by a photochemically-induced fluorescence method

“…Indeed, fenvalerate is not naturally fluorescent; however, fluorescent photoproducts can be obtained by UV irradiation. As reported in several previous studies of our research group, the PIF method is based on the photochemical transformation of naturally non-fluorescent pesticides into fluorescent photoproduct(s) under UV irradiation [22][23][24][25]. In the present paper, we optimized our PIF method by fixing suitable excitation and emission wavelengths, and by investigating the effect of solvent and irradiation time on the fenvalerate PIF properties.…”