Quantitative determination of emerging contaminants, solvent stabilizers and fullerene nanomaterials, in biological and environmental systems

To determine the impact of emerging environmental contaminants on human and environmental health, quantitative analytical methods are required. Analysis of emerging contaminants is hampered by their widely varying physical-chemical properties. Therefore quantitative analytical methods must be developed to determine the behavior of emerging contaminants in environmental systems.;A quantitative analytical method based on liquid-liquid extraction coupled to liquid chromatography-mass spectrometry (LC-MS) with electrospray ionization method was developed for a suite of fullerenes, C60-C98. The method was applied during a toxicological assay to determine loss of C 60 from solution and uptake of C60 by the embryonic zebrafish. The method utilizes an isotopically enriched internal standard, 13 C60, and achieves recoveries of 90% and 93% for C 60 from zebrafish embryo homogenate extracts and 1% DMSO in aqueous exposure water solutions with precision as determined by the relative standard deviation of 2 and 7%, respectively. When the method was applied to toxicology assay to determine the time course of C60 concentration in the aqueous exposure solution and embryo homogenate phase, >50% of the C 60 was lost from solution due to sorption to the exposure plate and uptake by the embryonic zebrafish increased over the course of the 12 hour exposure. The aqueous phase concentration that caused 50% mortality, LC 50, was determined to initially be 130 mug/L and was associated with an embryo phase concentration, LD50, of 0.079 mug/g zebrafish embryo.;A quantitative analytical method based on solid phase extraction in-vial elution, gas chromatography tandem mass spectrometry was developed for two solvent stabilizers, dioxane and THF, in groundwater. With the developed method, recoveries of 98% and 95% are achieved for dioxane and THF, respectively, with precision as determined by the relative standard deviation of <6%. Method quantitation limits were 0.31 mug/L for dioxane and 3.1 mug/L for THF. The method was applied to groundwater samples collected from a site impacted by chlorinated solvents. Dioxane concentrations (2800 +/- 60 mug/L) exceeded THF (71 +/- 2 mug/L) or 1,1,1-trichloroethane (980 +/- 30 mug/L). Furthermore, the areal extent of dioxane contamination greatly exceeded that of either THF or the chlorinated solvents.