Measuring nonpolar organic contaminant partitioning in three Norwegian sediments using polyethylene passive samplers.
ABSTRACT Freely dissolved pore water concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), penta- and hexachlorobenzene (PeCB and HCB), octachlorostyrene (OCS), p,p'-DDE and p,p'-DDD were measured in bottom sediments from three sites in Norway. Sediments were from Aker Brygge, site of a former shipyard in the inner part of Oslofjord, Frierfjord in the Grenlandsfjord area, impacted during the 50 year-long activity of a magnesium smelter plant, and from Kristiansand harbour, site with high industrial activity. Low density polyethylene (LDPE) membrane samplers were exposed to these sediments in laboratory incubation under constant and low-level agitation for periods of 1, 2, 6, 13, 23 and 50 days. Freely dissolved pore water concentrations were estimated from contaminant masses accumulated and sampling rates obtained from the measurement of kinetics of dissipation of performance reference compounds (PRCs). Marked differences in freely dissolved PAH concentrations and resulting organic carbon-normalised sediment-pore water partition coefficients, logK(TOC), between these three sediments could be observed despite the generally similar total sediment concentrations. In contrast with the PAH data, partitioning of PCBs and other organochlorine compounds (OCs) was relatively similar in all three sediments. For sediments from Frierfjord and Kristiansand, logK(TOC) values were lower for PCBs/OCs than for PAHs, indicating higher availability. Similar partitioning of PAHs and PCBs/OCs was found for sediments from Aker Brygge. No simple logK(oc)-logK(ow) relationships could model these data successfully. These results support the notion that the assessment of the risk posed by these compounds present in sediments in most cases requires actual measurement of contaminant availability.
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ABSTRACT: Among the different organic pollutants, persistent organic pollutants and emerging organic contaminants (EOCs) are of particular concern due to their potentially dangerous effects on the ecosystems and on human health. In the framework of the analysis of some of these organic pollutants in water samples, sorptive extraction devices have proven to be adequate for their monitoring. The efficiency of four commercially available and low-cost polymeric materials [polypropylene, poly(ethylene terephthalate), Raffia, and polyethersulfone (PES)] for the simultaneous extraction of 16 organic compounds from five different families from environmental water samples was evaluated in this work. Firstly, the homogeneity of the sorbent materials was confirmed by means of Raman spectroscopy. After the optimization of the parameters affecting the extraction and the liquid desorption steps, it was found that PES showed the largest efficiencies for slightly polar analytes and, to a lesser extent, for nonpolar analytes. Additionally, Raffia rendered good extraction efficiencies for nonpolar compounds. Thus sorptive extraction methods followed by large volume injection-programmable temperature vaporizer-gas chromatography-mass spectrometry were validated using PES and Raffia as sorbent materials. The validation of the method provided good linearity (0.978 < r (2) < 0.999 for PES and 0.977 < r (2) < 0.999 for Raffia), adequate repeatability (below 19 % and 14 % for PES and Raffia, respectively), and low method detection limits (low ng · l(-1) level). Finally, these materials were applied to the analysis of contaminants in environmental water samples.Environmental Science and Pollution Research 01/2014; · 2.76 Impact Factor
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ABSTRACT: Passive sampling represents a cost-effective approach and is more representative than grab sampling for the determination of contaminant concentrations in freshwaters. In this study, we performed the calibration of a promising tool, the passive Stir Bar Sorptive Extraction (SBSE), which has previously shown good performances for semi-quantitative monitoring of pesticides in a field study. We determined the sampling rates and lag-phases of 18 moderately hydrophobic to hydrophobic agricultural pesticides (2.18 < log Kow < 5.11) from different chemical classes including triazines, substituted ureas, triazoles and organophosphate compounds. We also realised an elimination experiment to identify a performance reference compound (PRC). A flow-through calibration experiment was realised for 7 days at constant concentrations of target pesticides in tap water, under controlled temperature (20 °C) and flow velocity (2.5 cm s−1). Sampling rates were between 1.3 and 121 mL d−1 with satisfactory RSD for most pesticides (9-47%), and poor repeatability for 3 hydrophobic pesticides (59-83%). Lag-phases for all target pesticides were shorter than 2 h, demonstrating the efficiency of passive SBSE for the integration of transient concentration peaks of these contaminants in surface waters. The role of flow velocity on pesticide uptakes was investigated and we assumed a water boundary layer-controlled mass transfer for 5 pesticides with log Kow > 3.3. Among these pesticides, we selected fenitrothion to evaluate its elimination, along with its deuterated analogue. Results showed 82% elimination of both compounds over the 7-day experiment and isotropic exchange for fenitrothion, making fenitrothion-d6 a promising PRC candidate for in situ applicationsJournal of Chromatography A 03/2014; · 4.61 Impact Factor
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ABSTRACT: Triolein-containing semipermeable membrane devices (SPMDs) and butyl rubber (BR) based sorbents were employed as passive samplers in 14 coastal stations of Turkey including shipyards and marinas to characterize time-integrated levels of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) and their relationship to potential pollution sources. Passive samplers of SPMDs and BR sorbents were deployed for 30 days in the spring of 2012. The maximum concentrations of total PAH and PCB compounds sequestered by SPMDs were 3338 ng g− 1 SPMD and 4247 pg g− 1 SPMD. (END)-I and DDT-related compounds were dominant OCP compounds for most of the sites in passive samplers. Total PAH concentrations in SPMDs were found 1.2 to 8 times higher than the concentrations in BRs. However, BR sorbents were able to sample some PAHs which could not be sampled by SPMDs. The concentrations of PCBs and OCPs in BRs were similar or higher than SPMDs. SPMD-data were used to estimate the average ambient water concentrations of the contaminants. Two existing theoretical approaches have been used to derive the concentrations of hydrophobic pollutants in the ambient waters. The results were found very similar and range from 7318 to 183864 pg L− 1 for PAHs, from 2 to 186 pg L− 1 for PCBs, and from 98 to 848 pg L− 1 for OCPs. Furthermore, a simple numerical model was designed to estimate the boat-related water concentrations in marinas by using the seawater data supplied by SPMDs. The model was mainly built on the water concentration and the capacities of a particular marina and then applied to two sites in the second marina. A good correlation was found between the model outputs and SPMD-water data.Environment International 12/2014; 73:85–93. · 5.66 Impact Factor