An artificial estrogen receptor through combinatorial imprinting

Polymeric sorbents targeting endocrine-disrupting estrogen active compounds (EAC) were prepared by terpolymer imprinting using 17b-estradiol (E2) as template. From a group of eight functional monomers representing Brønsted acids, bases, hydrogenbond donors and acceptors, as well as p-interacting monomers, a terpolymer library that comprises all possible binary combinations of the functional monomers was prepared. Binding tests revealed that imprinted polymers exhibit a markedly higher affinity for E2 compared to nonimprinted polymers (NIPs) or polymers prepared by using single functional monomers. A combination of methacrylic acid (MAA) and p-vinylbenzoic acid offered a particularly promising lead polymer, displaying an imprinting factor of 17 versus 2.4 for a benchmark polymer prepared by using only MAA as functional monomer. The saturation capacities ascribed to imprinted sites were four to five times higher for this polymer compared to previously reported imprinted polymers. NMR titrations and moleculardynamics simulations corroborated these results, indicating an orthogonal preference of the two functional monomers with respect to the E2 3-OH and 17-OH groups. The optimized polymer exhibited a retentivity for EACs that correlates with their inhibitory effect on the natural receptor. By using the optimized molecularly imprinted polymers (MIPs) in a model water-purification system, they were capable of completely removing ppb levels of a small group of EACs from water. This is in contrast to the performance of nonimprinted polymers and well-established sorbents for water purification (e.g., active carbon), which still contained detectable amounts of the compounds after treatment

Spatiotemporal distribution of the bacterial contamination of agricultural and domestic wastewater discharged to a drainage ditch (Sinaloa, Mexico)

The agricultural drainage water from the Sinaloa valley (Mexico) is often reused in agriculture and aquaculture before reaching coastal water bodies. Discharged water must be of good quality to maintain the health of ecosystems and prevent damage to the organisms that compose them. This research determined the occurrence of coliforms in a drainage ditch known as La Michoacana (Sinaloa) that receives contaminated water from agricultural and urban sources. A section of 3.6 km was studied during 2013 and samples were obtained monthly from five equidistant sampling sites. Each water sample was analyzed for total coliform (TC) and fecal coliform (FC) content, pH, salinity, temperature, and dissolved oxygen percentage (%DO). The sampling sites with the highest bacterial contamination were associated with direct discharges of domestic wastewater and those with the lowest to the output drain. The performance of this agricultural ditch decreased the concentration of coliforms, with median and average values of 96% and 87% for TC, and 98% and 85% for FC, respectively. The most common bacteria were Escherichia coli (67.7%), Kluyvera cryocrescens (10.2%), and Enterobacter agglomerans (6.3%). Coliform concentration was positively correlated with temperature and negatively with %DO. The ditch improved the microbiological quality of the water, demonstrating remediation activities in the system. Proper management and maintenance of agricultural drainage ditches would favorably impact the health and biodiversity, as well as the intensive aquaculture and agricultural activities of the Sinaloa valley

Identification of roxarsone metabolites produced in the system: soil – chlorinated water – light by using HPLC-ICP-MS/ESI-MS, HPLC-ESI-MS/MS and high resolution mass spectrometry (ESI-TOF-MS)

Roxarsone (4-hydroxy-3-nitrophenylarsonic acid) in contact with soil of volcanic origin and chlorine containing water generated a set of organoarsenicals. The transformation products were identified with element-specific (ICP-MS) as well as molecular-specific (ESI-MS) detection after their HPLC separation. The identification of the main transformation products by means of ESI-MS, ESI-MS/MS and ESI-TOF-MS adduce evidence of chlorinated phenylarsonic acids and a phenylarsine oxide derivative which contains arsenic in the trivalent state. Traces of chlorine in water used for sorption experiments are suggested to be responsible for the formation of chlorinated products. After irradiation of a roxarsone solution with visible light, different transformation product so far not identified were detected

The lowland stream monitoring dataset (KgM, Kleingewässer-Monitoring) 2018, 2019

Plant protection products in the environment are partly responsible for the progressive loss of biodiversity. The mostly insufficient ecological status of surface waters is often explained by habitat degradation and excessive nutrient input. But what role do plant protection products play in this context? The Kleingewässermonitoring (KgM) project provides a worldwide unique quantitative assessment of the impact of pesticides from diffuse agricultural sources on small and medium-sized streams. The dataset comprises 124 monitoring stream sections all over Germany covering a wide pollution gradient where consistent measurements were carried out in 2018 and 2019 during the major pesticide application period from April to July. These measurements include event-driven sampling to record surface rainfall-induced short-term peak concentrations in addition to regular grab sampling of pesticides and a wide range of other pollutants resulting in more than 1,000 water samples. All further relevant anthropogenic and environmental parameters reigning ecological stream quality were recorded comprehensively (morphological and stream bed structure, temperature, flow velocity, dissolved oxygen, pH, catchment land use, stream profile). The dataset also contains effect monitoring data featuring sampled invertebrate communities and bioassay analyses of water samples. The data enables an assessment of pesticide exposure and related effects as well as the analysis of complex causal relationships in streams