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USGS2020

American eels produce and release bile acids that vary across life stage

The American eel ( Anguilla rostrata ) is an imperilled fish hypothesized to use conspecific cues, in part, to coordinate long‐distance migration during their multistage life history. Here, holding water and tissue from multiple American eel life stages was collected and analysed for the presence, profile and concentration of bile acids. Distinct bile acid profiles were identified in glass, elver, yellow eel and silver eel holding waters using ultraperformance liquid chromatography high‐resolution mass spectrometry and principal component analysis. Taurochenodeoxycholic acid, taurodeoxycholic acid, cholic acid, deoxycholic acid, taurolithocholic acid and taurocholic acid were detected in whole tissue of American glass eels and elvers, and in liver, intestine and gallbladder samples of late‐stage yellow eels. Bile acids were not a major component of silver eel washings or tissue. This study is novel because little was previously known about bile acids produced and emitted into the environment by American eels. Future behavioural studies could evaluate whether any bile acids produced by American eels influence conspecific migratory behaviour.

Journal of Fish Biology↗

USGS1996

Optimization of the Ames/salmonella mutagenicity assay for use with extracts of aquatic sediments

Non-mutagenic components interfered with the ability of the standard Ames/salmonella assay to detect mutagenicity in extracts of contaminated Great Lakes sediments. The use of gel permeation chromatography (GPC) to remove these macromolecules from methylene chloride extracts prior to Ames testing enhanced the likelihood of transfer of mutagenic components into dimethyl sulf oxide (the assay solvent). Therefore, to optimize the assay's sensitivity we pre-treated sediment extracts using GPC and increased metabolic activity through the use of a 30% S9 mix. Increasing the level of Aroclor 1254-induced rat liver S9, typically used to metabolically activate promutagens, had the additional beneficial effect of reducing the cytotoxicity of the extracts. As applied in this study, the Ames assay can serve as a sensitive test for screening the mutagenic potential of large numbers of uncharacterized sediment extracts.

Journal of Great Lakes Research↗

USGS1985

Chemical investigations of wolf (Canis lupus) anal-sac secretion in relation to breeding season

The volatile constituents of wolf anal-sac secretions were examined via capillary gas chromatography and compared among intact males, females, castrate males, ovariectomized females, and anosmic and pinealectomized males and females. Some chemical compounds were deemed significantly different ( t test, 95% confidence level) among the groups both during and outside of the mating season, implying that the volatile components of anal-sac secretion can be used to communicate information regarding gender or endocrine state. As a result of treating the anal sac with antibiotics, some of these compounds, including 1-octen-3-ol and indole, were implicated as being products of microbial action. In addition, short-chain carboxylic acids were investigated and essentially no significant variations were seen among the groups.

Journal of Chemical Ecology↗

USGS1970

Organochlorine insecticide residues in soils and soil invertebrates from agricultural lands

Soils and earthworms and other soil invertebrates were collected from 67 agricultural fields in eight States. Samples were analyzed by gas chromatography for DDE, DDD, DDT, aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide, and gamma-chlordane insecticides. Organochlorine insecticides in soils averaged 1.5 ppm, dry weight, and in earthworms, 13.8 ppm. Residues in earthworms averaged nine times that in soils. Residues ranged from a trace to 19.1 ppm in soils and from a trace to 159.4 ppm in earthworms. Residues in beetle larvae from two fields averaged 0.6 ppm; in snails from two fields, 3.5 ppm; and in slugs from four fields, 89.0 ppm. Amounts of insecticides in earthworms varied directly with amounts in soils. Coefficients of correlation between residues in soils and residues in earthworms usually were significant for DDE, DDD, and DDT regardless of crop or soil type.

Pesticides Monitoring Journal↗

USGS2002

Movement of atrazine and deethylatrazine through a midwestern reservoir

The three-dimensional visualization of atrazine and deethylatrazine in a reservoir was determined by five "snapshots" over a one-year period using immunoassay analyses, confirmed by gas chromatography-mass spectrometry and visualized with a three-dimensional computer program. The surveys were conducted in Perry Lake in Kansas and showed that spring runoff laden with triazine herbicides entered the reservoir and did not mix immediately. Concentrations varied threefold between the inlet and the public water supply intakes located at the opposite end of the reservoir. The concentration range in the outflow varied much less than the concentration in the reservoir because of mixing throughout the season near the dam and outflow. A major conclusion from the study was that multiple analyses by a low-cost immunoassay technique coupled with computer visualization software gave a good three-dimensional view of the mass of herbicide present in a drinking water reservoir.

Journal - American Water Works Association↗

USGS1990

Selenium speciation methods and application to soil saturation extracts from San Joaquin Valley, California

Methods to determine soluble concentrations of selenite, selenate, and organic Se were evaluated on saturation extracts of soil samples collected from three sites on the Panoche Creek alluvial fan in the western San Joaquin Valley, California. The methods were used in combination with hydride-generation atomic-absorption spectrometry for detection of Se, and included a selective chemical-digestion method and three chromatographic methods using XAD-8 resin, Sep-Pak C 18 cartridge, and a combination of XAD-8 resin and activated charcoal. The chromatography methods isolate dissolved organic matter that can inhibit Se detection by hydride-generation atomic-absorption spectrometry. Isolation of hydrophobic organic matter with XAD-8 did not affect concentrations of selenite and selenate, and the isolated organic matter represents a minimal estimation of organic Se. Ninety-eight percent of the Se in the extracts was selenate and about 100% of the isolated organic Se was associated with the humic acid fraction of dissolved organic matter. The depth distribution of Se species in the soil saturation extracts support a hypothesis that the distribution of soluble Se and salinity in these soils is the result of evaporation from a shallow water table and leaching by irrigation water low in Se and salinity.

California↗

USGS2020

Determination of malachite green residues in the eggs, fry, and adult muscle-tissue of rainbow-trout (Oncorhynchus-mykiss)

Malachite green, an effective antifungal therapeutant used in fish culture, is a known teratogen. We developed a method to simultaneously detect both the chromatic and leuco forms of malachite green residues in the eggs, fry, and adult muscle tissue of rainbow trout ( Oncorhynchus mykiss ). Homogenates of these tissues were fortified with [ 14 C] malachite green chloride and extracted with 1% (v/v) acetic acid in acetonitrile or in methanol. The extracts were partitioned with chloroform, dried, redissolved in mobile phase, and analyzed by liquid chromatography (LC) with postcolumn oxidation of leuco malachite green to the chromatic form. LC fractions were collected every 30 s for quantitation by scintillation counting. Recoveries of total [ 14 C] malachite green chloride residue were 85 and 98% in eggs fortified with labeled malachite green at concentrations of 0.5 and 1.00 μg/g, respectively; 68% in fry similarly fortified at a concentration of 0.65 μg/g; and 66% in muscle homogenate similarly fortified at a level of 1.00 μg/g. The method was tested under operational conditions by exposing adult rainbow trout to 1.00 mg/L [ 14 C] malachite green chloride bath for 1 h. Muscle samples analyzed by sample oxidation and scintillation counting contained 1.3 and 0.5 μg/g total malachite green chloride residues immediately after exposure and after a 5-day withdrawal period, respectively.

Journal of AOAC International↗

USGS2019

Assessing the chemistry and bioavailability of dissolved organic matter from glaciers and rock glaciers

As glaciers thaw in response to warming, they release dissolved organic matter (DOM) to alpine lakes and streams. The United States contains an abundance of both alpine glaciers and rock glaciers. Differences in DOM composition and bioavailability between glacier types, like rock and ice glaciers, remain undefined. To assess differences in glacier and rock glacier DOM we evaluated bioavailability and molecular composition of DOM from four alpine catchments each with a glacier and a rock glacier at their headwaters. We assessed bioavailability of DOM by incubating each DOM source with a common microbial community and evaluated chemical characteristics of DOM before and after incubation using untargeted gas chromatography–mass spectrometry‐based metabolomics. Prior to incubations, ice glacier and rock glacier DOM had similar C:N ratios and chemical diversity, but differences in DOM composition. Incubations with a common microbial community showed that DOM from ice glacier meltwaters contained a higher proportion of bioavailable DOM and resulted in greater bacterial growth efficiency. After incubation, DOM composition from each source was statistically indistinguishable. This study provides an example of how MS‐based metabolomics can be used to assess effects of DOM composition on differences in bioavailability of DOM. Furthermore, it illustrates the importance of microbial metabolism in structuring composition of DOM. Even though rock glaciers had significantly less bioavailable DOM than ice glaciers, both glacial types still have potential to be important sources of bioavailable DOM to alpine headwaters over the coming decades.

Colorado↗

USGS1997

Supercritical fluid carbon dioxide extraction and liquid chromatographic separation with electrochemical detection of methylmercury from biological samples

Using the coupled methods presented in this paper, methylmercury can be accurately and rapidly extracted from biological samples by modified supercritical fluid carbon dioxide and quantitated using liquid chromatography with reductive electrochemical detection. Supercritical fluid carbon dioxide modified with methanol effectively extracts underivatized methylmercury from certified reference materials Dorm-1 (dogfish muscle) and Dolt-2 (dogfish liver). Calcium chloride and water, with a ratio of 5:2 (by weight), provide the acid environment required for extracting methylmercury from sample matrices. Methylmercury chloride is separated from other organomercury chloride compounds using HPLC. The acidic eluent, containing 0.06 mol L-1 NaCl, insures the presence of methylmercury chloride and facilitates the reduction of mercury on a glassy carbon electrode. If dual glassy carbon electrodes are used, a positive peak is observed at -0.65 to -0.70 V and a negative peak is observed at -0.90V with the organomercury compounds that were tested. The practical detection limit for methylmercury is 5 X 10-8 mol L-1 (1 X 10-12 tool injected) when a 20 ??L injection loop is used.

International Journal of Environmental Analytical ↗

USGS2002

Analysis and detection of the herbicides dimethenamid and flufenacet and their sulfonic and oxanilic acid degradates in natural water

Dimethenamid [2-chloro-N-(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)acetamide] and flufenacet [N-(4-fluorophenyl)-N-(1-methylethyl)-2-(5-(trifluoromethyl)-1,3,4- thiadiazol-2-yl)oxy] were isolated by C-18 solid-phase extraction and separated from their ethanesulfonic acid (ESA) and oxanilic acid (OXA) degradates during their elution using ethyl acetate for the parent compound, followed by methanol for the polar degradates. The parent compounds were detected using gas chromatography-mass spectrometry in selected-ion mode. The ESA and OXA degradates were detected using high-performance liquid chromatography-electrospray mass spectrometry (HPLC-ESPMS) in negative-ion mode. The method detection limits for a 123-mL sample ranged from 0.01 to 0.07 μg/L. These methods are compatible with existing methods and thus allow for analysis of 17 commonly used herbicides and 18 of their degradation compounds with one extraction. In a study of herbicide transport near the mouth of the Mississippi River during 1999 and 2000, dimethenamid and its ESA and OXA degradates were detected in surface water samples during the annual spring flushes. For flufenacet, the only detections at the study site were for the ESA degradates in samples collected at the peak of the herbicide spring flush in 2000. The low frequency of detections in surface water likely is due to dimethenamid and flufenacet being relatively new herbicides. In addition, detectable amounts of the stable degradates have not been detected in ground water.

Journal of Agricultural and Food Chemistry↗

USGS1982

A rapid high-performance liquid-chromatographic method for simultaneously determining the concentrations of TFM and Bayer 73 in water during lampricide treatments

The high-performance liquid-chromatography (HPLC) procedure requires only minutes per sample, is specific, and is relatively sensitive (limit of detection < 0.005 mg/L for both chemicals). A combined buffer (pH 4) and internal standard (3-chlorodiphenylamine) reagent is added to the water sample, which is injected through a Sep Pak C 18 disposable cartridge. The cartridge adsorbs and retains both the lampricides and the internal standard. The quantitative elution of the three chemicals from the cartridge with a small volume of methanol effectively concentrates the sample and provides sample cleanup. The methanol extract is then analyzed directly by HPLC on an MCH 10 reverse phase column by using a methanol:0.01 mol/L acetate buffer (87:13, v:v) as the mobile phase at 2 mL/min and detected by ultraviolet spectrophotometry at 330 (or 254) nm. A microprocessor data system further facilitates the procedure by quantifying off-scale peaks and yielding results directly in units of concentration (mg/L).

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS1973

Determination of the association and dissociation of humic acid fractions by small angle X-ray scattering

A procedure has been devised for the fractionation of humic acid samples from different environments. This procedure involves fractionation of the sample by adsorption chromatography on a Sephadex G-50 column followed by chromatography on either a G-25 or a G-100 column. The fractions of the solutions are then examined by small angle X-ray scattering. Three different types of behavior have been detected among the humic acid fractions: (1) Some fractions show very little change in aggregation at pH values above 3.5. (2) One fraction forms aggregates at pH values above and below pH 7, but at pH 7 it is completely dissociated. (3) In some fractions the degree of aggregation decreases with increasing pH. However, even at pH values as high as 11.5 some large particles are still present. These differences in association behavior are due to the interaction of different attractive and repulsive forces. In many aggregating systems only one type of attractive force is dominant; however in humic acid systems hydrogen bonding, π bonding between planar aromatic moieties, and other coulombic interactions apparently all play a role in the formation of molecular aggregates.

Journal of Research of the U.S. Geological Survey↗

USGS1991

Rotenone persistence in freshwater ponds: Effects of temperature and sediment adsorption

The persistence of rotenone was compared between a cement-lined pond (0.04 hectare) and an earthen-bottom pond (0.02 hectare) treated with 5 μL Noxfish/L (250 μg rotenone/L) during spring, summer, and fall. Water temperatures on the days of treatment in each season were 8, 22, and 15°C, respectively. Both ponds were filled with pond water from a common source 1 week before each of the three treatments. Water samples (filtered and unfiltered) and sediment samples were analyzed by high-performance liquid chromatography to monitor the decrease of rotenone until residues were at or below the detection limit (<2.0 μg/L for water and < 25 ng/g for sediments). The loss of rotenone from water generally followed a first-order rate ofdecay. Rotenone disappeared two to three times faster in the earthen pond than in the concrete pond. The rotenone half-life times in the spring, summer, and fall treatments were 3.7, 1.3, and 5.2 d, respectively, in the concrete pond, and 1.8, 0.7, and 1.8 d in the earthen pond. Rates of decay in both ponds were directly correlated with water temperature. Filtered water samples from both ponds contained less rotenone than unfiltered water, indicating that some rotenone was bound to suspended material. The highest concentration of rotenone in sediment samples was 102 ng/g; residues decreased to below the detection limit within 14 d in the spring treatment and within 3 d in the summer and fall treatments.

North American Journal of Fisheries Management↗

USGS2002

Determination of vapor pressures for nonpolar and semipolar organic compounds from gas chromatographic retention data

Vapor pressures for nonpolar and moderately polar organochlorine, pyrethroid, and organophosphate insecticides, phthalate esters, and organophosphate flame retardants were determined by capillary gas chromatography (GC). Organochlorines and polycyclic aromatic hydrocarbons with known liquid-phase vapor pressures (P??L) (standard compounds) were chromatographed along with two reference compounds n-C20 (elcosane) and p,p???-DDT on a 1.0-m-long poly(dimethylsiloxane) bonded-phase (BP-1) column to determine their vapor pressures by GC (P??GC). A plot of log P??L vs log P??GC for standard compounds was made to establish a correlation between measured and literature values, and this correlation was then used to compute P??L of test compounds from their measured P??GC. P??L of seven major components of technical chlordane, endosulfan and its metabolites, ??-hexachlorocyclohexane, mirex, and two components of technical toxaphene were determined by GC. This method provides vapor pressures within a factor of 2 of average literature values for nonpolar compounds, similar to reported interlaboratory precisions of vapor pressure determinations. GC tends to overestimate vapor pressures of moderately polar compounds. ?? 1990 American Chemical Society.

Journal of Chemical and Engineering Data↗

USGS2010

Effect of diet on fecal and urinary estrogenic activity

The United States Environmental Protection Agency has identified estrogens from animal feeding operations as a major environmental concern, but few data are available to quantify the excretion of estrogenic compounds by dairy cattle. The objectives of this study were to quantify variation in estrogenic activity in feces and urine due to increased dietary inclusion of phytoestrogens. Ten Holstein heifers were assigned to 2 groups balanced for age and days pregnant; groups were randomly assigned to treatment sequence in a 2-period crossover design. Dietary treatments consisted of grass hay or red clover hay, and necessary supplements. Total collection allowed for sampling of feed refusals, feces, and urine during the last 4 d of each period. Feces and urine samples were pooled by heifer and period, and base extracts were analyzed for estrogenic activity (estrogen equivalents) using the yeast estrogen screen bioassay. Feces and urine samples collected from 5 heifers were extracted and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify excretion of 7 phytoestrogenic compounds. Excretion of 17-β estradiolequivalents in urine was higher and tended to be higher in feces for heifers fed red clover hay (84.4 and 120.2 mg/d for feces and urine, respectively) compared with those fed grasshay (57.4 and 35.6 mg/d). Analysis by LC-MS/MS indicated greater fecal excretion of equol, genistein, daidzein, coumestrol, and formononetin by heifers fed red clover hay (1634, 29.9, 96.3, 27.8, and 163 mg/d, respectively) than heifers fed grass hay (340, 3.0, 46.2, 8.8, and 18.3 mg/d, respectively). Diet had no effect on fecal biochanin A or 2-carbethoxy-5, 7-dihydroxy-4’-methoxyisoflavone. Four phytoestrogens were detected in urine (2-carbethoxy-5, 7-dihydroxy-4’-methoxyisoflavone, daidzein, equol, and formononetin) and their excretion was not affected by diet. Identifying sources of variation in estrogenic activity of manure will aid in the development of practices to reduce environmental estrogen accumulation.

Journal of Dairy Science↗

USGS2014

Pharmacokinetics of hydromorphone hydrochloride after intravenous and intramuscular administration of a single dose to American kestrels (Falco sparverius)

Objective —To determine the pharmacokinetics of hydromorphone hydrochloride after IV and IM administration in American kestrels ( Falco sparverius ). Animals —12 healthy adult American kestrels. Procedures —A single dose of hydromorphone (0.6 mg/kg) was administered IM (pectoral muscles) and IV (right jugular vein); the time between IM and IV administration experiments was 1 month. Blood samples were collected at 5 minutes, 1 hour, and 3 hours (n = 4 birds); 0.25, 1.5, and 9 hours (4); and 0.5, 2, and 6 hours (4) after drug administration. Plasma hydromorphone concentrations were determined by means of liquid chromatography with mass spectrometry, and pharmacokinetic parameters were calculated with a noncompartmental model. Mean plasma hydromorphone concentration for each time was determined with naïve averaged pharmacokinetic analysis. Results —Plasma hydromorphone concentrations were detectable in 2 and 3 birds at 6 hours after IM and IV administration, respectively, but not at 9 hours after administration. The fraction of the hydromorphone dose absorbed after IM administration was 0.75. The maximum observed plasma concentration was 112.1 ng/mL (5 minutes after administration). The terminal half-life was 1.25 and 1.26 hours after IV and IM administration, respectively. Conclusion and Clinical Relevance —Results indicated hydromorphone hydrochloride had high bioavailability and rapid elimination after IM administration, with a short terminal half-life, rapid plasma clearance, and large volume of distribution in American kestrels. Further studies regarding the effects of other doses, other administration routes, constantrate infusions, and slow release formulations on the pharmacokinetics of hydromorphone hydrochloride and its metabolites in American kestrels may be indicated.

American Journal of Veterinary Research↗

USGS1992

Identification of persistent anionic surfactant-derived chemicals in sewage effluent and groundwater

Preparative isolation and fractionation procedures coupled with spectrometric analyses were used to identify surfactant-derived contaminants in sewage effluent and sewage-contaminated groundwater from a site located on Cape Cod, Massachusetts. Anionic surfactants and their biodegradation intermediates were isolated from field samples by ion exchange and fractionated by solvent extraction and adsorption chromatography. Fractions were analyzed by 13 C nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry. Carboxylated residues of alkylphenol polyethoxylate surfactants were detected in sewage effluent and contaminated groundwater. Linear alkylbenzenesulfonates (LAS) were identified in sewage effluent and groundwater. Groundwater LAS composition suggested preferential removal of select isomers and homologs due to processes of biodegradation and partitioning. Tetralin and indane sulfonates (DATS), alicyclic analogs of LAS, were also identified in field samples. Although DATS are a minor portion of LAS formulations, equivalent concentrations of LAS and DATS in groundwater suggested persistence of alicyclic contaminant structures over those of linear structure. Sulfophenyl-carboxylated (SPC) LAS biodegradation intermediates were determined in sewage effluent and groundwater. Homolog distributions suggested that SPC containing 3–10 alkyl-chain carbons persist during infiltration and groundwater transport. Surfactant-derived residues detected in well F 300-50 groundwater have a minimum residence time in the range of 2.7–4.6 yr. LAS detected in groundwater at 500 m from infiltration has been stable over an estimated 50–500 half lives.

Journal of Contaminant Hydrology↗

USGS2008

Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms

Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin, which is given to lactating cows as a feed. By weight, monensin can be the most significant antibiotic used in a dairy farm. This study investigates the potential of monensin to move from dairy operations into the surrounding ground water. Using two dairy farms in California as study sites, we twice collected samples along the environmental pathway-from flush lanes, lagoon waters, and shallow ground water beneath the dairies and beneath its associated manured fields. Monensin concentrations were determined using solid-phase extraction and liquid chromatography-tandem mass spectrometry with positive electrospray ionization. Monensin was detected in all of the flush lane and lagoon water samples. Theoretical maximum concentration estimated from the actual dosing rate and the theoretical excretion rate assuming no attenuation was one order of magnitude greater than observed concentrations, suggesting significant attenuation in the manure collection and storage system. Monensin was also detected, at levels ranging from 0.04 to 0.39 microg L(-1), in some of the ground water samples underneath the production area of the dairy but not from the adjacent manured fields. Concentrations in ground water immediately downgradient of the lagoons were one to two orders of magnitude lower than the concentrations detected in lagoons, suggesting attenuation in the subsurface. The data suggest the possibility of monensin transport into shallow (2-5 m) alluvial ground water from dairy management units, including manure storage lagoons and freestalls occupied by heifers, lactating cows, and dry cows.

Journal of Environmental Quality↗