What is the spatial-temporal behavior of a low, medium and high adsorptive compound in two contrasting natural sediments in OECD 218/219 test systems?

Artificial sediment used in studies according to OECD 218/219 (Sediment Water Chironomid Toxicity Test Using Spiked Sediment/Water) does not necessarily mirror the characteristics of natural sediments. To investigate the influence of sediment characteristics on the spatial-temporal behaviors of bixafen (KfOM = 2244 mL/g), fluopyram (KfOM = 162 mL/g) and N,N-dimethylsulfamide (KfOM ≈ 0 mL/g), experiments according to OECD 218/219 with two contrasting natural sediments were conducted. The silt loam sediment provided a high content of organic matter (OM) (13.

What is the actual exposure of organic compounds on Chironomus riparius? - A novel methodology enabling the depth-related analysis in sediment microcosms.

A novel active sampling method enabled determination of sediment depth profiles revealing the spatial distribution of model compounds N,N-dimethylsulfamide, fluopyram and bixafen (low, medium, high adsorption affinity) in sediment microcosms according to OECD Test 218/219 (Sediment-Water Chironomid Toxicity Test Using Spiked Sediment/Spiked Water). After the overlying water was removed, plastic tubes were inserted into the sediment and the microcosms were frozen. For depth-related analysis, each "sediment core" was mounted in a cutting device and sawed into three 5-mm-slices, respectively (top, middle, bottom).

Unraveling microbial turnover and non-extractable residues of bromoxynil in soil microcosms with C-isotope probing.

Bromoxynil is a widely used nitrile herbicide applied to maize and other cereals in many countries. To date, still little is known about bromoxynil turnover and the structural identity of bromoxynil non-extractable residues (NER) which are reported to occur in high amounts. Therefore, we investigated the microbial turnover of C-labeled bromoxynil for 32 days.

Quantitative Identification of Biogenic Nonextractable Pesticide Residues in Soil by (14)C-Analysis.

Quantification of nonextractable residues (NER) of pesticides in soil is feasible by use of radioactively labeled compounds, but structural information on these long-term stabilized residues is usually lacking. Microorganisms incorporate parts of the radiolabeled ((14)C-) carbon from contaminants into microbial biomass, which after cell death enters soil organic matter, thus forming biogenic nonextractable residues (bioNER). The formation of bioNER is not yet determinable in environmental fate studies due to a lack of methodology.

Life stage- dependent bioconcentration of a nonylphenol isomer in Daphnia magna.

Bioaccumulation is an important aspect for the fate and effects of xenobiotics in the environment. In this study we used a radiolabeled nonylphenol isomer to investigate the bioconcentration in Daphnia magna at different ages. Apart from the total radioactivity we measured the metabolism of p353-NP in D.

Occurrence of a nitro metabolite of a defined nonylphenol isomer in soil/sewage sludge mixtures.

Uniformly [14C]-ring-labeled 4-(3,5-dimethyl-3-heptyl)phenol (353-nonylphenol) is a highly relevant isomer of the technical nonylphenol mixture. We studied the sorption, desorption, and degradation of the synthesized isomer in an agricultural sandy loam at various soil/sewage sludge ratios. Sorption of 353-nonylphenol was high and differed with the amount of suspended soil in water.