A comparison of two methods for fractionating complex mixtures in preparation for XXXX analysis.

@entity211 @entity137 @entity2555 @entity212 @entity16648 @entity3014 @entity2556 @entity3015 @entity526 @entity5383
Chemical fractionation is a widely used tool for the chemical and toxicological characterization of complex mixtures. The objective of this research was to compare two frequently employed methods for fractionating a wood preserving waste (WPW) containing @entity2555 ( @entity2556 ) and @entity211 ( @entity212 ). The first method involved fractionation of the WPW into acid, base, and neutral fractions using a liquid-liquid acid/base/neutral (A/B/N) technique. The second method utilized @entity5383 column chromatography to produce two fractions, A1 and A2. Gas chromatography and mass spectrometry were used to quantify the chemical components in all fractions. The @entity5383 method recovered 473,338 mg of total @entity2556 (tPAHs) per kilogram crude, while the A/B/N method yielded only 193,379 mg tPAHs/kg crude. In contrast, the A/B/N method recovered 13.7 mg @entity212 /kg crude while the @entity5383 method yielded only 0.5 mg @entity212 /kg crude. Three bioassays were used to determine the @entity137 of the crude extract and fractions. The neutral and A1 fractions contained the highest levels of tPAHs and @entity3014 ( @entity3015 ) but failed to induce a positive response in the Salmonella/microsome assay with concentrations containing as much as 1800 and 2500 ng BaP/plate, respectively. In the @entity526 prophage induction assay, the acid fraction, which contained 472 mg @entity212 /kg fraction, induced a positive response, as did the base fraction, which did not contain detectable @entity212 . Significant reduction of gap junctional intercellular communication in hepatic cells occurred with the crude extract and acid, base, and neutral fractions. Overall, the results of these bioassays suggest that @entity212 genotoxicity was expressed in the acid fraction, whereas the cumulative genotoxicity of genotoxic @entity2556 appeared to be masked in the isolates from either fractionation method. The optimal fractionation method for a mixture of @entity16648 and @entity2556 may involve a refined hybrid method.
