Assessment of the environmental persistence and long-range transport of endosulfan.

Concentrations of the insecticide endosulfan (α- and ß-isomer) and its degradation product endosulfan sulfate in air, seawater and soil are calculated with the global environmental fate model CliMoChem. As model input, physicochemical properties of all three compounds were assembled and a latitudinally and temporally resolved emission inventory was generated. For concentrations in air, model and measurements are in good agreement; a bimodal seasonality with two peaks in spring and fall as it is observed in Arctic air is reproduced by the model. For seawater, the agreement of model and measurements depends on the values of the hydrolysis activation energy of endosulfan used in the model; with relatively high values around 100 kJ/mol, model results match field data well. The results of this assessment of the levels, persistence, and global distribution of endosulfan are also relevant for the evaluation of endosulfan as a Persistent Organic Pollutant under the Stockholm Convention.

Quantification of five isoflavones and coumestrol in various solid agroenvironmental matrices using ¹³c3-labeled internal standards.

We developed and validated three different sample preparation and extraction methods followed by HPLC-MS/MS (negative electrospray ionization) analysis for the quantification of estrogenic isoflavones (formononetin, daidzein, equol, biochanin A, and genistein) and coumestrol in red clover, soil, and manure. Plant and manure samples were solid-liquid extracted, whereas soil was extracted with accelerated solvent extraction. Absolute recoveries were between 80 and 93%, 20 and 30%, and 14 and 91% for plant, soil, and manure samples, respectively. Relative recoveries ranged from 75 to 105% for all matrices, indicating that isotope-labeled internal standards (¹³C3-formononetin, ¹³C3-daidzein, ¹³C3-equol, ¹³C3-biochanin A, and ¹³C3-genistein) were capable to compensate for losses during analysis. The limits of detection in red clover, soil, and manure were 3-9 µg/g(dryweight(dw)), 0.6-8.2 ng/g(dw), and 34.2 ng/g(dw) to 17.0 µg/g(dw), respectively. Formononetin was the most dominant compound in red clover plants (up to 12.5 mg/g(dw)) and soil (up to 3.3 µg/g(dw)), whereas equol prevailed in manure (up to 387 µg/g(dw)).