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Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/ToF-MS) was used for the analysis of thia-arenes and aza-arenes in standard mixtures containing 45 polycyclic aromatic compounds (PACs), and in the aromatic fraction of snowpack samples collected from the Athabasca oil sands area of Alberta, Canada. The GC columns used included a shape-selective liquid-crystalline stationary phase (LC-50) and a high-polarity ionic-liquid stationary phase (SLB-IL60), both in the first dimension. A fast diffusion and low-polarity nano-stationary phase (NSP-35) and a mid-polarity stationary phase (Rxi-17), were used in the second dimension, respectively. Both configurations showed good repeatability for retention times in the first and second dimensions, peak areas and peak heights. Instrument detection limits ranged from 0.5 to 10 pg µL−1 for both configurations. In general, the LC-50×NSP-35 configuration favoured the separation of isomeric compounds by using more of ...

Levels of persistent organic pollutants (POP), such as polychlorinated biphenyls (PCB), are high in many Arctic top predators, including the Arctic fox (Vulpes lagopus). The aim of this study was to examine possible endocrine-disruptive effects of dietary POP exposure in male juvenile Arctic foxes in a controlled exposure experiment. The study was conducted using domesticated farmed blue foxes (Vulpes lagopus) as a model species. Two groups of newly weaned male foxes received a diet supplemented with either minke whale (Baleneoptera acutorostrata) blubber that was naturally contaminated with POP (exposed group, n = 5 or 21), or pork (Sus scrofa) fat (control group, n = 5 or 21). When the foxes were 6 mo old and had received the 2 diets for approximately 4 mo (147 d), effects of the dietary exposure to POP on plasma concentrations of testosterone (T), thyroid hormones (TH), thyroid-stimulating hormone (TSH), retinol (vitamin A), and tocopherol (viramin E) were examined. At sampling, the total body concentrations of 104 PCB congeners were 0.1 ± 0.03 μg/g lipid weight (l.w.; n = 5 [mean ± standard deviation]) and 1.5 ± 0.17 μg/g l.w. (n = 5) in the control and exposed groups, respectively. Plasma testosterone concentrations in the exposed male foxes were significantly lower than in the control males, being approximately 25% of that in the exposed foxes. There were no between-treatment differences for TH, TSH, retinol, or tocopherol. The results suggest that the high POP levels experienced by costal populations of Arctic foxes, such as in Svalbard and Iceland, may result in delayed masculine maturation during adolescence. Sex hormone disruption during puberty may thus have lifetime consequences on all aspects of reproductive function in adult male foxes.

(2008). Biomagnification of mercury in a West African crater lake (Lake Bosomtwe, Ghana) SIL Proceedings, 1922-2010: Vol. 30, No. 4, pp. 647-650.

An analytical method for the simultaneous determination of organochlorine pesticides (OCPs), phthalate esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) in soils is described. Soils were ultrasonically extracted with a mixture of acetone–petroleum ether (1:1, v/v). Two equal portions of combined extracts were fractionated with different polarity solvents via Florisil and silica gel chromatography, to determine OCPs and PAEs, and PAHs, respectively. Reliable recoveries were obtained, which were 92–121% for OCPs, 68–141% for PAEs, and 75–120% for PAHs. The limits of detection were 0.001–0.017 ng g−1 for OCPs, 0.001–0.022 µg g−1 for PAEs, and 0.002–0.042–µg g−1 for PAHs. In order to check the method, soils collected from the Beijing region were analysed. The average concentrations were 39–91 ng g−1 for OCPs, 1–2 µg g−1 for PAEs, and 0.24–2.12 µg g−1 for PAHs in urban and rural areas, respectively. Gas chromatography–mass spectrometry (GC–MS) was used to confirm the analyzed compounds by gas chromatog...

Photochemistry of two polychlorodibenzofurans (PCDFs), 1,2,4,7,8‐pentachlorodibenzofuran (1,2,4,7,8‐P5CDF) (1) (3.870 × 10‐6M) and 1,2,3,4,7,8‐H6CDF (2) (1.272 × 10‐6M) dissolved in water‐acetonitrile (1:1 v/v) was investigated using wavelengths near 313nm. The quantum yields for the direct phototransformation of P5CDF 1 and H6CDF 2 were found to be (1.295±0.087) x 10‐2 and (6.964±0.234) × 10‐4, respectively. The quantum yields and absorption spectral data for PCDFs 1 and 2 together with solar intensity data from the literature were used to determine the direct sunlight (environmental) photolytic transformation first‐order rate constants of these pollutants present in aquatic systems under conditions of varying sunlight during spring, summer, fall, and winter season. For instance, in summer, the calculated midday, midseason sunlight photolysis first‐order rate constants for furans 1 and 2 near the surface of water bodies at 40° north latitude were 3.082 ±0.207 and (11.630 ± 0.391)× 10‐2h‐1, respectively; ...

The degradation of methoxychlor (14C‐ring‐labelled) was studied under laboratory conditions in Take and pond sediments (water‐sediment ratio, 10–20:1) incubated under various redox conditions at 22.5 or 10°C. Methoxychlor degraded rapidly in sediments with half‐lives of

In 1979 and 1980, outdoor artificial ponds were treated with 14C-permethrin (labelled at either the cyclopropyl or methylene position) at 0.028 kg/ha (15 ug/L). Uptake of permethrin by duckweed and hydrosoil was monitored by direct combustion, TLC-autoradiography, HPLC, and liquid scintillation counting. Rapid loss of permethrin from the water coincided with the detection of five degradation products in the water at concentrations below 2.0 ug/L. The products were cis- and trans-cyclopropyl acid, phenoxybenzoic acid, and phenoxybenzyl alcohol, and an unknown non-cleaved product of permethrin. Permethrin was readily sorbed by duckweed but was not persistent. Permethrin residues in the hydrosoil, which was the major sink for permethrin added to the ponds, were persistent and were detected at 420 days post-treatment. Cis-permethrin was more persistent in the hydrosoil than the trans-permethrin. The results indicated that permethrin in water was short-lived at an application rate of 15 ug/L because of the rapid degradation of permethrin in the water and sorption of permethrin by the hydrosoil and vegetation. However, at one year post-treatment, permethrin residues were still detected in the hydrosoil at 1.0 ug/kg.

The distribution and fate of four 14C‐ring‐labelled triaryl/alkyl phosphate esters (2‐ethylhexyl‐diphenyl phosphate (EHDP), t‐butylphenyldiphenyl phosphate (tBPDP), tri‐m‐cresyl phosphate (mTCP) and triphenyl phosphate (TPP)) were compared at 25,10 and 2°C in pond and river sediments (sediment : water ratio 1: 10). Half‐lives in sediment ranged from 2.8 days for TPP to 5.3 days for EHDP at 25°C and from 11.9 to 19.1 days for the same compounds at 2°C. Incubation of the four compounds in sediment (25°C) under air or nitrogen purge had little influence on the rate of degradation of the compounds. Total CO2 evolution ranged from 4% for EHDP to 21% from mTCP and was similar in sediments under air and nitrogen purge (redox potentials +362 to — 51mV). Radioactivity extractable from sediment consisted mainly of intact phosphate esters and small amounts of more polar products ( < 10 % of total 14C) which could be separated from the intact esters by reverse‐phase TLC and HPLC. Diaryl phosphates were minor degradat...

A method is described for the determination of niclosamide (2′,5-dichloro-4′-nitrosalicylanilide) in river water and sediment. River water is extracted by shaking with ethyl acetate. Sediment is shaken with methanol: water (4:I), the mixture is centrifuged and the methanol is evaporated. The sediment extract is then partitioned with methylene chloride and the extracts are cleaned up on a Florisil column. Niclosamide can be analysed, after methylation with methyl iodide, by gas chromatography with electron-capture or alkali-flame detection, or directly by high pressure liquid chromatography with a UV absorbance (313 nm) detector. Recoveries of niclosamide ranged from 99 to 116% in fortified river water and 73 to 126% in fortified pond sediment samples.