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Tondeur Y.,Analytical Perspectives | Nestrick T.,4520 Washington Street | Silva H.A.,S.A. de C.V. | Vining B.,Analytical Perspectives | Hart J.,Analytical Perspectives
Chemosphere | Year: 2010

A method for the determination of all polychlorinated dibenzo-p-dioxin (PCDDs) and polychlorinated dibenzofurans (PCDFs), and hexachlorobenzene (HCB) contained in production batches of pentachlorophenol (PCP) samples is presented. The method uses two sub-samples of the PCP sample to provide an effective dynamic range of 1:40,000,000. Following extraction of the samples and fractionation of the sample extracts, the extracts are analyzed by HRGC/HRMS, and the resulting data from both sub-samples are combined to generate the final data for each sample. Data from the analysis of 47 samples using this method are presented and show a ratio of concentrations of octachlorinated dibenzofuran (OCDF) to 2,3,7,8-tetrachlorinated dibenzofuran (TCDF) of approximately 4,000,000:1. The results show that four congeners dominate the ITEQ, which has an average value of 634μgkg-1 (429μgkg-1 WHO 2005 TEQ) in those samples. © 2010 Elsevier Ltd.

Tondeur Y.,Analytical Perspectives | Vining B.,Analytical Perspectives | Mace K.,Analytical Perspectives | Mills W.,Mills Consulting Inc. | Hart J.,Analytical Perspectives
Chemosphere | Year: 2012

In late 1990s, USEPA/FDA made an important connection regarding the presence of elevated levels of dioxins (e.g., 1500ngkg -1 TEQ) in ball clays mined in Mississippi (USA) from a geological deposit dated to ∼40million years (Mississippi Embayment) that stretches over several states (northern part of Mississippi to Kentucky) and levels of dioxins in selected animal food sources. Following a recent beach nourishment program along the mid-Atlantic coast of the US, a number of dark gray, blue tinted nuggets of varying sizes were found on beach strands and near the shoreline. Using the presence of these balls of clay (shape, color, and knowledge regarding their use in pottery) on the beach, together with our direct experience analyzing ball clays for dioxins, we made a possible association between these clays and elevated dioxins. Concerns regarding the potential of nourishment programs to cause severe damage to our beaches drove us to test the dioxin content of nourishment exposed clays. A number of the nuggets, along with freshly dredged and deposited sand (collected the morning after nourishment) with the same coloration, and others (sun-bleached), collected approximately 2weeks after the completion of the nourishment efforts, were analyzed for the presence of PCDD/Fs, PCBs, and selected semi-volatile chlorinated organics. The clay PCDD/F WHO2005-TEQs (dry weight; ND=DL; EMPC=EMPC) ranged from 0.41 to 5.78ngkg -1 with an average of 2.64ngkg -1, whereas the sand sample's TEQs ranged from 0.18 to 0.31ngkg -1 PCDD/F WHO-2005, with an average of 0.22ngkg -1. The average total tetra- through octachlorinated dibenzo-p-dioxin concentration was 2700ngkg -1 (with a maximum of 5800ngkg -1) for the clays and 8.5ngkg -1 (with a maximum of 16.8ngkg -1) for the sand samples. The congener 2,3,7,8-TCDD (TEF=1) was detected in half of the clay samples (0.11-0.77ngkg -1). All of the clay and sand samples displayed an unambiguous and dominating 1,4,6,9-chlorination pattern across homolog groups. No other chlorinated aromatics were detected above background levels. The observations, along with the absence or an extremely low level of polychlorinated dibenzofurans, together with the mineralogical analysis, supports the conclusion that off-shore dredging activities are reaching reservoir sources containing dioxin-tainted, smectic/kaolinite clay minerals. Subsequent beach erosion provides additional environmental releases over time, as buried balls of clay from previous nourishment efforts become exposed. © 2012 Elsevier Ltd.

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