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Filters: Tags: {"scheme":"National Agricultural Library Thesaurus"} (X) > partyWithName: Michelle L Hladik (X)

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Neonicotinoids have become the most widely used insecticides in world with rapid growth in applications as seed coatings. Nontarget organisms are exposed to concentrated levels of pesticidal active ingredients through ingestion of treated seeds. To better understand pesticide fate, analytical methods are necessary to rapidly screen and accurately quantitate contaminants in environmental and biological matrices. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is commonly employed for neonicotinoid analyses but requires expensive analytical instrumentation and potentially laborious sample preparation. Enzyme-linked immunosorbent assays (ELISAs) are efficient and sensitive alternative methods for neonicotinoid...
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Surface water samples were collected from four stream/agricultural drain sites in the Sacramento Valley of California to measure pesticides commonly applied to rice. Samples were collected weekly from May through August 2010 to capture the rice pesticide application season. Water samples were filtered (0.7 µm) and extracted via solid-phase extraction. Additionally, the filter paper was solvent extracted to measure suspended sediment-associated pesticides. Both fractions were analyzed via gas chromatography-mass spectrometry. A total of 89 pesticides and pesticide degradates were measured in the dissolved water phase, while 14 pyrethroid insecticides were measured in the suspended sediment-associated fraction (pyrethroids...
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Wild bee and butterfly samples were collected from the margins of agricultural fields located on five Conservation Areas in Missouri. In 2016 and 2017, samples were collected and composited by genera for a total of 90 samples. Samples were 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 spectrometry. Overall, 16 pesticides were detected. Pesticides detected in greater than 2% of the composite samples included: metolachlor (24%), tebuconazole (22%), atrazine (18%), imidacloprid desnitro (13%), bifenthrin (9%), flumetralin (9%), p,p’-DDD (6%), tebupirimfos (4%), fludioxonil (4%),...
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To better understand the exposure of wild bees to pesticides in an agricultural landscape, samples were collected from fields in northern California. Hedgerows are known to provide habitat for wild bees, but these bees may also be exposed to pesticides from nearby agricultural fields. The study included eight hedgerow sites located in an intensively managed agricultural landscape that includes almonds, (wine) grapes, rice, tomatoes, and walnuts. In addition to collecting both wild bees and honey bees, soil, flowers, and silicone passive sampling devices (PSD; staked near the hedgerows to sample the air) were also included. Sampling was conducted from April to June 2016, to coincide with peak bloom and bee activity...
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Applications of pesticides in agricultural and urban settings play an essential role in increasing crop yields, preserving food and materials, reducing pest-borne diseases, and eradicating or deterring pests. Pesticides are transported from their point of application to environmental media, including surface water. To better understand the fate of fate and transport of pesticides in the environment, analytical methods are necessary to measure pesticides in waters. Herein, a method is described for the extraction and analysis of pesticides and pesticide degradates in filtered surface water and paired suspended sediment samples. Water samples (~ 1 L) are filtered using 0.7 μm glass-fiber filters prior to being extracted...
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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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This data release includes sampling location, pesticide concentrations in passive samplers (silicone bands) and bees foraging in Conservation Reserve Program fields. Sampling took place during July and August of 2019. Fields were located on private land managed for the U.S. Department of Agriculture Conservation Reserve Program in eastern central Iowa, U.S.A.
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Lab-reared colonies of Bombus huntii (Hunt bumble bee) were deployed in a commercial cherry orchard in the spring of 2016. A fungicide formulation containing boscalid (25.2%) and pyraclostrobin (12.8%) was applied one time at the recommended label rate. Nectar and pollen were collected daily, beginning two days before spray application and continuing for ten days following. Nectar samples were extracted with acetonitrile and cleaned up using dispersive solid-phase extraction with primary-secondary amine, C18, and magnesium sulfate. Pollen samples were extracted with ethyl acetate. Both types of samples were analyzed by GC-MS/MS for boscalid and pyraclostrobin. Fungicide concentrations in nectar varied spatially...
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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 Fungicides in nectar and pollen collected by bumble bees in a cherry orchard Partitioning of six pyrethroid insecticides at varying salinities Concentrations of pesticides in multiple matrices to measure exposure of wild bees visiting pollinator hedgerows in northern California Pesticides in pollinator tissue collected from margins near agricultural fields in Conservation Areas of Missouri Pesticide concentrations in surface waters of the Sacramento Valley rice-growing region, 2010 Evaluation of ELISA for the Analysis of Imidacloprid in Plasma, Liver, and Fecal Matter A Multiresidue Method for the Analysis of Pesticides in Water using Solid-Phase Extraction with Gas and Liquid Chromatography-Tandem Mass Spectrometry (ver. 2.0, April 2023) Pesticide residues in passive samplers and bee tissue from Conservation Reserve Program fields across an agricultural gradient in eastern Iowa, USA, 2019 (ver 2.0, October 2023) Partitioning of six pyrethroid insecticides at varying salinities A Multiresidue Method for the Analysis of Pesticides in Water using Solid-Phase Extraction with Gas and Liquid Chromatography-Tandem Mass Spectrometry (ver. 2.0, April 2023) Concentrations of pesticides in multiple matrices to measure exposure of wild bees visiting pollinator hedgerows in northern California Pesticide concentrations in surface waters of the Sacramento Valley rice-growing region, 2010 Pesticides in pollinator tissue collected from margins near agricultural fields in Conservation Areas of Missouri Pesticide residues in passive samplers and bee tissue from Conservation Reserve Program fields across an agricultural gradient in eastern Iowa, USA, 2019 (ver 2.0, October 2023) Fungicides in nectar and pollen collected by bumble bees in a cherry orchard Evaluation of ELISA for the Analysis of Imidacloprid in Plasma, Liver, and Fecal Matter