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Carbograph 6, a new graphitized carbon black with a specific surface area of 203 m2 g−1, as measured by BET, both uncoated and coated with up to 12% ( w/w) of squalane, a non-polar stationary phase, has been studied by gas chromatographic determination of the enthalpy, entropy, and free energy of adsorption of a series of alkanes (C2−C6) and benzene. The data obtained are discussed and compared with those available in the literature for other graphitized carbon blacks. An example of a separation obtaned with Carbograph 6 is reported. [ABSTRACT FROM AUTHOR]

Some of the most commonly employed carbon blacks (Carbograph 1,2,4,5 from Lara and Carbopack X form Supelco), were evaluated by the BET surface characterization method for pore size distribution, porosity and specific surface. This information is often incomplete as furnished by manufacturers and is needed for a deeper understanding of carbon adsorption properties in chromatography. The data on surface characterization were obtained before and after graphitisation treatment (except for Carbopack X which could not be obtained in non-graphitized form). The nature of the active sites present on these carbons was investigated by BET analysis, atomic absorption and FT-IR. [ABSTRACT FROM AUTHOR]

A new graphitized carbon black, Carbograph 4, with a specific surface area of 240 m2 g−1 was studied in terms of enthalpy, entropy and free energy of adsorption, determined by gas chromatographic method on a series of alkanes (C2−C6) and on benzene. The changes in the isosteric heat and entropy of adsorption when a non-polar stationary phase (squalane) was added to the adsorbent were also investigated. The data obtained are discussed and compared to those present in the literature for other graphitized carbon blacks. Some examples of separations obtained with Carbograph 4 are reported. [ABSTRACT FROM AUTHOR]

A dualsorbent trap containing graphitized carbon blacks was used for the collection of volatile and semi-volatile organic pollutants from the atmosphere of different workplaces and from an above-ground parking lot. The method proved to be sensitive, simple and reliable. Thermal desorption and solvent extraction methods followed by GC-MS analysis were employed. [ABSTRACT FROM AUTHOR]

A new graphitized carbon black (Carbograph 5) with a specific surface area (560 m2 g−1) greater than those of commerically available graphitized carbons was studied by gas chromatography to determine the enthalpy, entropy, and free energy of adsorption of a series of alkanes (C2−C6). The adsorption properties were also investigated by considering changes in the isosteric heats and entropies of adsorption when a nonpolar stationary phase (squalane) was added to the adsorbent. The data obtained are discussed and compared with literature values for other graphitized carbon blacks. [ABSTRACT FROM AUTHOR]

A dualsorbent trap containing Carbograph 5, a new high specific-surface (560 m2·g−1) graphitized carbon black, and Carbograph 2 was tested in terms of the breakthrough volumes and desorption recoveries in order to verify its capability to trap and thermally desorb a mixture composed of the main classes of organic compounds. [ABSTRACT FROM AUTHOR]

A study was carried out of the recovery by solid phase extraction of the eleven most toxic polychlorinated biphenyls from water containing humic acids. Experiments were performed using water polluted with a humic acid (sodium salt) concentration of 9–18 mg L−1. The effect of humic acids on the recoveries was noticeable, especially where the more chlorinated congeners were concerned. The effect was also evident with river water containing naturally dissolved humic acids. A method for destroying humic acids prior to extraction was applied. The recoveries after the destruction of humic acids were in the range of 90%, even in the case of river water, demonstrating the applicability of the method to real samples. [ABSTRACT FROM AUTHOR]