Filters: Tags: Gas chromatography (X)
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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...
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...
Categories: Data;
Tags: USGS Science Data Catalog (SDC),
environment,
gas chromatography,
liquid chromatography,
mass spectroscopy,
This dataset presents the results of passive water sampling conducted at 2 sites in 2013 and 3 sites in 2014 in Lake Mead National Recreational Area. Polar Organic Chemical Integrative Samplers (POCIS) and Semipermeable Membrane Devices (SPMDs) were deployed in Las Vegas Bay and Overton Arm in 2013 and Las Vegas Bay, Boulder Basin, and Overton Arm in 2014. The samplers were analyzed for concentrations of polychlorinated biphenyls (PCBs), organochlorines (DDT-type compounds and their degradates), polybrominated biphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), waste indicators (WW), and yeast estrogen screen (YES) by the U.S. Geological Survey (USGS) at the Columbia Environmental Research Center (CERC)...
Categories: Data;
Tags: Boulder Basin,
Colorado River,
Lake Mead,
Lake Mead National Recreational Area,
Las Vegas,
Stable carbon and hydrogen isotopic data generated by off-line preparation and dual inlet mass spectrometric analysis used the determine the recommended values for the reference materials HCG-1, HCG-2, and HCG-3.
Categories: Data;
Tags: Energy Resources,
Gas geochemistry,
Isotope-ratio mass-spectrometry,
Reference materials,
Stable isotopes,
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...
This dataset presents the results of analysis of aquatic biota tissue samples, collected at 2 sites (Las Vegas Bay and Overton Arm) in 2013 and 2 sites (Las Vegas Bay, Boulder Basin, and Overton Arm) in 2014 in Lake Mead National Recreational Area. The tissue samples were analyzed for concentrations of more than 250 compounds and congeners of polychlorinated biphenyls (PCBs), organochlorine pesticides (DDT and its degradates), wastewater chemicals, and polybrominated diphenyl ethers (PBDEs) by the U.S. Geological Survey (USGS) at the Columbia Environmental Research Center (CERC) in Columbia, Missouri. Analysis methods include low-resolution, high-resolution, and full spectrum mass spectrometry and high-resolution...
Categories: Data;
Tags: Boulder Basin,
Colorado River,
Lake Mead,
Lake Mead National Recreational Area,
Las Vegas,
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