Geology topics

Jeffry A. Bernardy

Publications and source records attributed to Jeffry A. Bernardy.

4 recordsLinked to original sources

USGS2019

Determination of Antimycin-A in water by liquid chromatographic/mass spectrometry: single-laboratory validation

An LC/MS method was developed and validated for the quantitative determination and confirmation of antimycin-A (ANT-A) in water from lakes or streams. Three different water sample volumes (25, 50, and 250 mL) were evaluated. ANT-A was stabilized in the field by immediately extracting it from water into anhydrous acetone using SPE. The stabilized concentrated samples were then transported to a laboratory and analyzed by LC/MS using negative electrospray ionization. The method was determined to have adequate accuracy (78 to 113% recovery), precision (0.77 to 7.5% RSD with samples ≥500 ng/L and 4.8 to 17% RSD with samples ≤100 ng/L), linearity, and robustness over an LOQ range from 8 to 51 600 ng/L.

Journal of AOAC International↗

USGS2012

Evaluation of 3-trifluoromethyl-4-nitrophenol (TFM) residues following a lampricide treatment as a risk assessment to the endangered piping plover

To evaluate the risk to the federally endangered piping plover ( Charadrius melodus ) from exposure to 3-trifluoromethyl-4-nitrophenol (TFM) during a sea lamprey control treatment we collected and analyzed a series of water, sediment, and aquatic invertebrate samples for the presence of TFM before, during, and after treatment of the Little Two Hearted River, Luce County, Michigan in July 2008. Results of the analyses in water showed the treatment resulted in a maximum concentration of 1.14 mg/L TFM. Residues of TFM in water were greatest 50 m east of the mouth (0.73 mg/L TFM) and had decreased below detection at most of the sampling sites one day after treatment. Residues of TFM in sediment were greatest 50 m east of the mouth (105 ng/g TFM) with lower levels observed west of the mouth (3-5 ng/g TFM) the day of the treatment. Residues decreased rapidly and were below detection in most of the samples the day after treatment. Residues of TFM in caged mayflies were greatest one day after treatment (3,193 ng/g wet weight), decreased substantially by 4 days after treatment (74 ng/g), but were still present 8 days after treatment (80 ng/g). Based on results from this study the overall TFM exposure to adult piping plovers (0.425 mg/kg) was 85 times less than the estimated No Observable Effects Concentration (NOEC) of 36 mg/kg and was 17 times less than the NOEC for plover chicks (2.13 mg/kg) indicating the risk from sea lamprey control operations would likely be minimal.

Michigan↗

USGS2010

Chronic toxicity of diphenhydramine hydrochloride and erythromycin thiocyanate to Daphnia, Daphnia magna, in a continuous exposure test system

Diphenhydramine hydrochloride (DH; Benadryl™, an over-the-counter antihistamine) and erythromycin thiocyanate (ET; a commonly used macrolide antibiotic) are pharmaceutical compounds whose chronic toxicity to Daphnia magna had not been characterized. Continuous exposure to DH concentrations about 5 times greater than the maximum reported environmental concentration of 0.023 μg/L for 21 days or to ET concentrations about 40 times the maximum reported environmental concentration of 6 μg/L for 21 days did not significantly impact D . magna survival and production. In this study the no observable effect concentration for DH was 0.12 μg/L and for ET was 248 μg/L.

Bulletin of Environmental Contamination and Toxico↗

USGS2003

Residue depletion of oxytetracycline from fillet tissues of northern pike and walleye

The broad-spectrum antibacterial drug oxytetracycline (OTC) is used in the U.S. to treat certain diseases in salmonids and catfish. This study was conducted to support an extension of the OTC label to include all cool-water fish species cultured at U.S. public aquaculture facilities by satisfying human food safety requirements. Juvenile northern pike ( Esox lucius ; mean weight: 117 g) and walleye ( Stizostedion vitreum ; mean weight: 59 g) were fed OTC-medicated diets near the maximum legal treatment rate (82.7 mg OTC-HCl/kg fish/day for 10 days) and near the lower limit of the water temperature range for most disease outbreaks in these species (14 and 16 °C, respectively). Two trials were conducted simultaneously with northern pike, one using commercially medicated feed and the other using on-site OTC top-coated feed. A third trial was performed with walleye using on-site OTC top-coated feed. Fillet tissues were collected and OTC free base (OTC-base) concentrations were determined by high performance liquid chromatography. The maximum mean OTC-base concentrations in the fillet tissue were 319 ng/g in northern pike (skinless) and 721 ng/g in walleye (skin-on), both well below the current tolerance limit of 2000 ng/g OTC-base. The log-linear loss of OTC-base from the fillet tissues was monophasic, with terminal phase half-lives of 5.9 days in northern pike fed commercial medicated feed, 6.7 days in northern pike fed top-coated feed, and 10.5 days in walleye fed top-coated feed. The data supported a zero withdrawal time in juvenile northern pike and walleye fed OTC at the approved dose level for 10 days at water temperatures down to 14 and 16 °C respectively.

Aquaculture↗