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The compound 3-amino-4-hydroxyphenylarsonic acid (3-amino-HPAA) reacts with smectite to form a soluble azobenzene arsonic acid compound. This reaction is of particular interest because it provides a possible mechanism for the formation of a new type of arsenic compound in natural water systems. 3-Amino-HPAA is a degradation product excreted by chickens that are fed rations amended with roxarsone. Roxarsone is used to control coccidial intestinal parasites in most of the broiler chickens grown in the United States. The structure of the azobenzene arsonic acid compound was first inferred from negative-ion and positive-ion low-resolution mass-spectrometric analyses of the supernatant of the smectite suspension. Elemental...
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To evaluate the potential uptake and accumulation of pesticides in amphibians, American bullfrog (Lithobates catesbeianus) tadpoles were collected from surface water sites (four ponds and one reservoir) in 2021 near Mead, Nebraska. Sites were located in the landscape surrounding the AltEn ethanol plant, a plant which had previously received pesticide treated (coated) seeds. Tadpoles were collected in November 2021, these tadpoles hatched in June 2021. The tadpole tissues were dried, homogenized, and then extracted using acetonitrile at 100 °C. Samples were analyzed for 166 pesticides and degradates using both gas and liquid chromatography-tandem mass spectrometry. Overall, 14 pesticides and degradates were detected...
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To better understand the potential pesticide exposure, samples were collected from locations along two creeks in Pinnacles National Park and four creeks in nearby Bureau of Land Management (BLM) lands. Silicone bands were used as passive sampling devices (PSD) staked in the creek and above in the air (above the water line). Sampling was conducted in the summer from 2019 to 2021. PSDs were deployed for 2 to 4 weeks and sediment was collected once in 2020. PSDs were extracted via sonication with an organic solvent and sediment was extracted via pressurized liquid extraction and solid phase extraction cleanup. Samples were analyzed for 168 pesticides and degradates using both gas and liquid chromatography-tandem mass...
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This table reports major, minor, and trace element compositions of bulk drill core samples from the Duluth Complex, Minnesota. Major elements were measured using wavelength dispersive X-ray fluorescence (XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES); minor and trace elements were determined using ICP-AES, inductively coupled plasma mass spectrometry (ICP-MS), and hydride generation atomic absorption spectrometry (HGAAS). Total carbon, carbonate carbon, and total sulfur were also analyzed. Total carbon was measured by combustion followed by infrared detection on LECO instrumentation. Carbonate carbon in the bulk rock samples was determined as carbon dioxide by coulometric titration. Total...
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Japanese quail (Coturnix japonica) were orally dosed with pesticide-treated or control-untreated wheat seeds. Pesticide treated wheat seeds were analytically verified for active ingredients of imidacloprid, metalaxyl, tebuconazole, and fludioxonil. Pesticide and metabolite residues were measured in plasma, liver, brain, kidney, muscle, and excreta of exposed and control birds. Samples were extracted via solid phase extraction, pressurized liquid extraction, or sonication. Clean-up steps included protein precipitation followed by solid phase extraction. All samples were analyzed by liquid chromatography tandem mass spectrometry.
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To determine aqueous pyrethroid partitioning across a salinity gradient 20 mL Pyrex beakers were filled with 8 mL of deionized water at varying salinities (0, 0.5, 2, 6 ppt). Salinity was adjusted using a 10 ppt stock solution (made by diluting Instant Ocean into deionized water). The water samples were spiked with pyrethroids (bifenthrin, cyhalothrin, cyfluthrin, cypermethrin, deltamethrin, esfenvalerate, fenpropathrin) at 500 ng/L (pyrethroid stock solution was 0.25 ng/µL in acetone, 16 µL added to each beaker). Samples were equilibrated in the dark (beaker covered with aluminum foil and placed in a cardboard box; the first set was equilibrated for 24 hr, the second set for 120 hr). Each set of samples at a particular...


map background search result map search result map Major, Minor, and Trace Element Compositions of Bulk Drill Core Samples from the Duluth Complex, Minnesota Partitioning of six pyrethroid insecticides at varying salinities Concentrations of pesticides in silicone bands as passive samplers and sediment in Pinnacles National Park and Bureau of Land Management lands in San Benito County, California, 2019-2021 Pesticide Concentrations in American Bullfrog (Lithobates catesbeianus) Tadpoles Collected from Ponds and Reservoirs near Mead, Nebraska Partitioning of six pyrethroid insecticides at varying salinities Pesticide Concentrations in American Bullfrog (Lithobates catesbeianus) Tadpoles Collected from Ponds and Reservoirs near Mead, Nebraska Concentrations of pesticides in silicone bands as passive samplers and sediment in Pinnacles National Park and Bureau of Land Management lands in San Benito County, California, 2019-2021 Major, Minor, and Trace Element Compositions of Bulk Drill Core Samples from the Duluth Complex, Minnesota