Cyclodextrins (CDs), which possess a hydrophobic cavity, have a remarkable capacity to form inclusion complexes with various molecules through host-guest interactions It is well known that the usefulness of CDs is due to the combination of the inclusion properties and structural features of these molecules CDs are used extensively in separation science because CD-complexation phenomena offer a procedure of choice for separation of compounds and extraction processes, and provide a useful and versatile tool for protecting the environment The present review shows the advantages accruing from the use of adsorbents containing cyclodextrins, in particular in chromatographic separations and in waste water treatment The main goal of this review is to provide a summary of the information concerning the synthesis of materials containing CDs and to give a general overview of the different possible applications of CDs as sorbents in the field of separation techniques Recent and continuing interest in these adsorbents is evident from the number of papers that appear each year in the literature

Synthesis and applications of adsorbents containing cyclodextrins

The concentrations of benzo[a]pyrene and 11 other polycyclic aromatic hydrocarbons (PAHs) were analysed from 322 commercial, cured meat products and 14 home-grilled meat samples as part of the Estonian food safety monitoring programme during 2001-2005. The maximum acceptable concentration of 5 microg kg(-1) for benzo[a]pyrene was exceeded in 3.4% of samples. The highest PAH concentrations were detected in home-grilled pork samples. Using of disposable grilling unit resulted in 1.6 times higher PAH concentrations compared to the traditional wood-burning grill. The average intake of benzo[a]pyrene and sum of 12 PAHs from meat products was estimated for children (age 1-16 years) on the basis of an individual food consumption questionnaire and, for the general population, based on national food consumption data. The highest total PAH concentrations detected were 16 microg kg(-1) in smoked meat and ham, 19 microg kg(-1) in smoked sausage and 6.5 microg kg(-1) in smoked chicken samples. Since smoking and grilling are prevalent meat-cooking methods in Estonia, the impact of meat products is assessed to be significant in overall PAH intake.

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Polycyclic aromatic hydrocarbons (PAHs) in meat products and estimated PAH intake by children and the general population in Estonia.

Recent Advances in Adsorption Kinetic Models: Their Application to Dye Types

The adsorption and UV-protection properties of water-extract from honeysuckle whose main ingredient is chlorogenic acid onto wool were studied. The effect of initial pH on the adsorption was investigated, and the extent of adsorption was found to increase with decreasing pH in the range 2−7. Four kinetic equations, namely pseudo-first-order, pseudo-second-order, Elvoich, and intraparticle diffusion equations were employed to investigate the adsorption rates. The pseudo-second-order model provided the best fit to the experimental data and was indicated with the activation energy of 47.91 kJ mol−1. The equilibrium adsorption data were fitted by Freundlich, Langmuir, Redlich−Peterson, and Langmuir−Nernst isotherm models. The adsorption behavior accorded with Redlich−Peterson and Langmuir−Nernst models well. The honeysuckle extract showed good build-up properties, and the UV transmittance in the range of UVA and UVB of wool treated with honeysuckle extract decreased obviously while the ultraviolet protection ...

/pdf/adsorption-and-uv-protection-properties-of-the-extract-from-3vsyd27szv.pdf

Adsorption and UV Protection Properties of the Extract from Honeysuckle onto Wool

The determination of polycyclic aromatic hydrocarbons in smoked fish by gas chromatography mass spectrometry with positive-ion chemical ionization

1.

A thermodynamic derivation is given for the equation of molecular exchange adsorption from solutions.




2.

Some special forms of the equation have been found for adsorption on nonporous and porous adsorbents.




3.

An analysis of the simpler form of the equation for the cases where the ratio of the activity coefficients in the surface and volume phases is constant or equal to unity shows that it is possible to use the molecular exchange adsorption equation to describe the forms of the isotherms from solutions encountered in practice.

Theory of adsorption from nonelectrolyte solutions on solid adsorbents

http://link.springer.com/content/pdf/10.1007/BF00908016.pdf

Theory of adsorption from nonelectrolyte solutions on solid adsorbents: 1. Simplified analysis of the equation of the adsorption isotherm from solutions

Adsorption properties of polymer sorbents of the Styrosorb type in the preconcentration of polycyclic aromatic hydrocarbons from aqueous solutions were studied. Optimal conditions of extraction were determined. It was found that naphthalene and phenanthrene are most efficiently extracted with these sorbents.

Solid-Phase Extraction of Polycyclic Aromatic Hydrocarbons Using Polymer Sorbents

We have calculated the individual adsorption isotherms from solutions of chloroform-carbon tetrachloride on three adsorbents using only the data on adsorption from solutions.

Adsorption from solutions of nonelectrolytes on solid adsorbents

Stable nano-sized nickel particles are prepared using the radiation-chemical synthesis in reverse micelles. Adsorption properties of raw silica (silochrome, S-120), the silochrome modified by a micelle-forming compound (AOT), and the silochrome modified by the nano-sized nickel particles are studied using gas chromatography method. The retention times for different test-compounds at different temperatures are determined for these adsorbents. Specific retention volumes of the test-compounds, as well as the thermodynamic adsorption characteristics, are determined. After the modification, the initial adsorption heat for n-hydrocarbons increases, which points out to the higher surface roughness of the modified samples. For the nickel-nanoparticle-modified silica, the contribution of specific interactions of polar compounds is less than that for the unmodified silica; this can be explained by screening the active centers (OH-groups) of the silica gel by the metal nanoparticles. The silica polarity decreases after the modification. The gas chromatography method allows detecting the difference in the properties of nanocomposites containing Ni- and NiO-nanoparticles.

O. G. Larionov

Papers

Theory of adsorption from nonelectrolyte solutions on solid adsorbents

Theory of adsorption from nonelectrolyte solutions on solid adsorbents: 1. Simplified analysis of the equation of the adsorption isotherm from solutions

Solid-Phase Extraction of Polycyclic Aromatic Hydrocarbons Using Polymer Sorbents

Adsorption from solutions of nonelectrolytes on solid adsorbents

A gas-chromatography study of adsorption properties of silica modified by stable nickel nanoparticles obtained in reverse micelles under γ-radiation