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Chemical structure of gyphosate, aminomethylphosphonic acid, glufosinate, and their 9-fluorenylmethyl-chloroformate derivatized compounds.
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The U.S. Geological Survey method (0-2141-09) presented is approved for the determination of glyphosate, its degradation product aminomethylphosphonic acid (AMPA), and glufosinate in water. It was was validated to demonstrate the method detection levels (MDL), compare isotope dilution to standard addition, and evaluate method and compound stability...
Contexts in source publication
Context 1
... (N-(phosphonomethyl)glycine, fig. 1), a non-selective, post-emergence herbicide, has been widely used since it was released commercially in 1974, and is one of the world's most widely used agrochemical herbicides (Monsanto Company, 2002;Cox, 2004). In 2004, glyphosate usage estimates indicated that between 103 and 113 million pounds were applied annually to crops in the ...
Context 2
... is degraded primarily by microbial metabolism producing aminomethylphosphonic acid (AMPA; Rueppel and others, 1977). Glufosinate is similar to glyphosate in chemical structure and use (Cox, 1996; fig 1). The three compounds are polar and extremely soluble in water, and require derivatization for chromatographic separation. ...
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Citations
... The USGS Kansas Organic Geochemistry Research Laboratory (OGRL) analyzed samples for glyphosate, glufosinate, and aminomethylphosphonic acid (AMPA). For this analysis, 3 125-mL combusted amber-glass bottles were filled to the shoulder with water passed through a pre-rinsed (site water) 0.7-μm pore-size glass fiber syringe filter, and analyses were done using methods described by Meyer et al. (2009). ...
Long-term (2010-19) water-quality monitoring on the Colorado River downstream from Moab Utah indicated the persistent presence of Bioactive Chemicals (BC), such as pesticides and pharmaceuticals. This stream reach near Canyonlands National Park provides critical habitat for federally endangered species. The Moab wastewater treatment plant (WWTP) outfall discharges to the Colorado River and is the nearest potential point-source to this reach. The original WWTP was replaced in 2018. In 2016-19, a study was completed to determine if the new plant reduced BC input to the Colorado River at, and downstream from, the outfall. Water samples were collected before and after the plant replacement at sites upstream and downstream from the outfall. Samples were analyzed for as many as 243 pesticides, 109 pharmaceuticals, 20 hormones, 51 wastewater indicator chemicals, 20 metals, and 8 nutrients. BC concentrations, hazard quotients (HQs), and exposure activity ratios (EARs) were used to identify and prioritize contaminants for their potential to have adverse biological effects on the health of native and endangered wildlife. There were 22 BCE with HQs >1, mostly metals and hormones; and 23 BCE with EARs >0.1, mostly hormones and pharmaceuticals. Most high HQs or EARs were associated with samples collected at the WWTP outfall site prior to its replacement. Discharge from the new plant had reduced concentrations of nutrients, hormones, pharmaceuticals, and other BC. For example, all 16 of the hormones detected at the WWTP outfall site had maximum concentrations in samples collected prior to the WWTP replacement. The WWTP replacement had less effect on instream concentrations of metals and pesticides, BC whose sources are less directly tied to domestic wastewater. Study results indicate that improved WWTP technology can create substantial reductions in concentrations of non-regulated BC such as pharmaceuticals, in addition to regulated contaminants such as nutrients.
... Chemical analyses included four different analytical methods that have all been previously described: 1) 226 pesticides and pesticide transformation products were quantified at the USGS National Water Quality Laboratory using direct aqueous-injection liquid chromatography-tandem mass spectrometry (LC-MS/MS; Sandstrom et al., 2016); 2) six neonicotinoid insecticides were quantified at the USGS California Water Science Center using solid-phase extraction followed by LC-MS/MS (Hladik & Calhoun, 2012); and 3) glyphosate was quantified at the USGS Organic Geochemistry Research Laboratory using two methods: 72 samples across all 16 sites were analyzed for glyphosate by enzyme-linked immunosorbent assay (ELISA; Mahler et al., 2017), and to confirm the ELISA results, a subset of 29 samples were analyzed for glyphosate and glyphosate transformation product aminomethylphosphonic acid using LC-MS/MS by isotope dilution with online solid-phase extraction (Meyer et al., 2009). All measured compounds with supporting metadata can be found in the Supporting Information, Table S3, and the final concentrations are provided in the Supporting Information, Table S4. ...
Watersheds of the Great Lakes Basin (USA/Canada) are highly modified and impacted by human activities including pesticide use. Despite labeling restrictions intended to minimize risks to nontarget organisms, concerns remain that environmental exposures to pesticides may be occurring at levels negatively impacting nontarget organisms. We used a combination of organismal‐level toxicity estimates (in vivo aquatic life benchmarks) and data from high‐throughput screening (HTS) assays (in vitro benchmarks) to prioritize pesticides and sites of concern in streams at 16 tributaries to the Great Lakes Basin. In vivo or in vitro benchmark values were exceeded at 15 sites, 10 of which had exceedances throughout the year. Pesticides had the greatest potential biological impact at the site with the greatest proportion of agricultural land use in its basin (the Maumee River, Toledo, OH, USA), with 72 parent compounds or transformation products being detected, 47 of which exceeded at least one benchmark value. Our risk‐based screening approach identified multiple pesticide parent compounds of concern in tributaries of the Great Lakes; these compounds included: eight herbicides (metolachlor, acetochlor, 2,4‐dichlorophenoxyacetic acid, diuron, atrazine, alachlor, triclopyr, and simazine), three fungicides (chlorothalonil, propiconazole, and carbendazim), and four insecticides (diazinon, fipronil, imidacloprid, and clothianidin). We present methods for reducing the volume and complexity of potential biological effects data that result from combining contaminant surveillance with HTS (in vitro) and traditional (in vivo) toxicity estimates. Environ Toxicol Chem 2022;00:1–18. Published 2022. This article is a U.S. Government work and is in the public domain in the USA. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
... However, the method does not work for all types of pesticides, and several compounds were absent from the analysis. For example, glyphosate is one of the most widely used pesticides in the United States and Canada (Anderson et al., 2021;Benbrook, 2016;Wieben, 2020) but is not included in the pesticide analytical schedule because it is difficult to isolate (Meyer et al., 2009;Sandstrom et al., 2015). Third, toxicity evaluations continually change and benchmarks can be revised. ...
To help meet objectives of the Great Lakes Restoration Initiative with regard to increasing knowledge about toxic substances, 223 pesticides and pesticide transformation products were monitored in 15 Great Lakes tributaries using polar organic chemical integrative samplers (POCIS). A screening‐level assessment of their potential for biological effects was conducted by computing toxicity quotients (TQs) for chemicals with available U.S. Environmental Protection Agency (EPA) Aquatic Life Benchmark values. Additionally, Exposure Activity Ratios (EAR) were calculated using information from the EPA ToxCast database. Between 16 and 81 chemicals were detected per site, with 97 unique compounds detected overall, for which 64 could be assessed using TQs or EARs. Ten chemicals exceeded TQ or EAR levels of concern at two or more sites. Chemicals exceeding thresholds included seven herbicides (2,4‐dichlorophenoxyacetic acid, diuron, metolachlor, acetochlor, atrazine, simazine, and sulfentrazone), a transformation product (deisopropylatrazine), and two insecticides (fipronil and imidacloprid). Watersheds draining agricultural and urban areas had more detections and higher concentrations of pesticides compared to other land uses. Chemical mixtures analysis for ToxCast assays associated with common modes of action defined by gene targets and adverse outcome pathways (AOP) indicated potential activity on biological pathways related to a range of cellular processes including, xenobiotic metabolism, extracellular signaling, endocrine function, and protection against oxidative stress. Use of gene ontology databases and the AOP knowledgebase within the R‐package ToxMixtures highlighted the utility of ToxCast data for identifying and evaluating potential biological effects and adverse outcomes of chemicals and mixtures. Results have provided a list of high priority chemicals for future monitoring and potential biological effects warranting further evaluation in laboratory and field environments. This article is protected by copyright. All rights reserved. Environ Toxicol Chem 2022;00:0–0.
... Insect and water samples were extracted for pesticides according to previously described methods (Hladik at al. 2008, Meyer et al. 2009, Hladik and Calhoun 2012Supporting Information). Given the small mass of individual adult aquatic insects, multiple individuals were composited by taxonomic order in each wetland for pesticide tissue analysis. ...
Contaminants alter the quantity and quality of insect prey available to terrestrial insectivores. In agricultural regions, the quantity of aquatic insects emerging from freshwaters can be impacted by insecticides originating from surrounding croplands. We hypothesized that, in such regions, adult aquatic insects could also act as important vectors of pesticide transfer to terrestrial food webs. To estimate insect‐mediated pesticide flux from wetlands embedded in an important agricultural landscape, semi‐permanently and temporarily ponded wetlands were surveyed in cropland and grassland landscapes across a natural salinity gradient in the Prairie Pothole Region of North Dakota (USA) during the bird breeding season in 2015 and 2016 (N = 14 and 15 wetlands, respectively). Current‐use pesticides, including the herbicide atrazine and the insecticides bifenthrin and imidacloprid, were detected in newly emerged insects. Detection probabilities were similar in insects emerging from agricultural and grassland wetlands. Biomass of emerging aquatic insects decreased 43% and insect‐mediated pesticide flux increased 50% along the observed gradient in concentrations of insecticides in emerging aquatic insects (from 3 to 577 ng total insecticide g‐1 insect). Overall, adult aquatic insects were estimated to transfer between 2‐µg and 180‐µg total pesticide wetland‐1 d‐1 to the terrestrial ecosystem. In one of the two study years, biomass of emerging adult aquatic insects was also 73% lower from agricultural than grassland wetlands and was dependent on salinity. Our results suggest that accumulated insecticides reduce availability of adult aquatic insect prey for insectivores and potentially increase insectivore exposure to insect‐borne pesticides. Adult aquatic insects retain pesticides across metamorphosis and may expose insectivores living near both agricultural and grassland wetlands to dietary sources of toxic chemicals. This article is protected by copyright. All rights reserved.
... The USGS Kansas Organic Geochemistry Research Laboratory (OGRL) in Lawrence, Kansas, analyzed samples for glyphosate, glufosinate, and aminomethylphosphonic acid (AMPA). For this analyses, three 125-mL combusted amber-glass bottles were filled to the shoulder with water passed through a 0.7-μm pore-size syringe filter, and analyses were conducted using methods described by Meyer et al. (2009). ...
Two non-native carp species have invaded the Illinois Waterway and are a threat to Great Lakes ecosystems. Poor water quality in the upper Illinois Waterway may be a factor contributing to the stalling of the carp population front near river mile 278. In 2015, the U.S. Geological Survey collected 4 sets of water samples from two sites upstream and 4 sites downstream from river mile 278, and one tributary. Each sample was analyzed for up to 649 unique constituents of which 287 were detected including 96 pesticides, 62 pharmaceuticals, 39 wastewater indicator chemicals, 29 metals, 19 volatile organic compounds (VOCs), 6 disinfection by-products (DBPs), 5 hormones, and 5 carboxylic acids. Potential for bioactivity was estimated by comparing chemical concentrations to aquatic life or human health criteria and to in-vitro bioactivity screening results in the U.S Environmental Protection Agency ToxCast™ database. The resulting hazard quotients and exposure-activity ratios (EARs) are toxicity indexes that can be used to rank potential bioactivity of individual chemicals and chemical mixtures. This analysis indicates that several bioactive chemicals (BCs) including: carbendazim, 2,4-D, metolachlor, terbuthylazine, and acetochlor (pesticides); 1,4-dioxane (VOC); metformin, diphenhydramine, sulfamethoxazole, tramadol, fexofenadine, and the anti-depressants (pharmaceuticals); bisphenol A, 4-nonylphenol, galaxolide, 4-tert-octylphenol (wastewater indicator chemical); lead and boron (metals); and estrone (hormone) all occur in the upper Illinois Waterway at concentrations that produce elevated EARs values and may be adversely affecting carp reproduction and health. The clear differences in water quality upstream and downstream from river mile 278 with higher contaminant concentrations and potential bioactivity upstream could represent a barrier to carp range expansion.
... Derivatisation with FMOC-Cl increases the retention of glyphosate, AMPA, and glufosinate on reversed phase stationary phases making it possible to separate the derivatised analytes from highly polar carbohydrates which constitute the bulk of the honey matrix. Numerous groups have employed online solidphase extraction methods for the determination of one or more of glyphosate, AMPA, and glufosinate in water samples after offline derivatisation using FMOC-Cl (Vreeken et al. 1998;Meyer et al. 2009;Sanchis et al. 2012;Poiger et al. 2017). The advantages of online SPE versus offline SPE are three-fold: firstly to automate the clean-up procedure thereby reducing labour and preparation time; secondly to permit the direct transfer of the analytes of interest from the extraction column/cartridge to the analytical column; and thirdly to facilitate the refinement of the conditions under which the analytes are trapped and subsequently eluted for direct determination. ...
A simple method was developed for the simultaneous determination of glyphosate, its main degradation product (aminomethylphosphonic acid), and glufosinate in honey. Aqueous honey solutions were derivatised offline prior to direct analysis of the target analytes using online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry. Using the developed procedure, accuracies ranging from 95.2% to 105.3% were observed for all analytes at fortification levels of 5, 50, and 150 μg kg⁻¹ with intra-day precisions ranging from 1.6% to 7.2%. The limit of quantitation (LOQ) was 1 μg kg⁻¹ for each analyte. Two hundred honey samples were analysed for the three analytes with AMPA and glyphosate being most frequently detected (99.0% and 98.5% of samples tested, respectively). The concentrations of glyphosate were found to range from <1 to 49.8 μg kg⁻¹ while those of its degradation product ranged from <1 to 50.1 μg kg⁻¹. The ratio of glyphosate to AMPA was found to vary significantly amongst the samples where both analytes were present above the LOQ. Glufosinate was detected in 125 of 200 samples up to a maximum concentration of 33.0 μg kg⁻¹.
... In the purified extract, glyphosate, AMPA and glufosinate were derivatized with 200 μL of a FMOC-Cl (60 mg mL −1 in acetonitrile) for 60 min at room temperature. The derivatization reaction was stopped by addition of 30 μL concentrated formic acid (98-100%), and the samples were stabilized with 150 μL 1 M EDTA prior to LC-MS/MS analyses (Botero-Coy et al., 2013;Hanke et al., 2008;Ibáñez et al., 2005;Meyer et al., 2009;Skeff et al., 2016;Wang et al., 2016a;Wang et al., 2016b). ...
Glyphosate is the best-selling and the most-used broad-spectrum herbicide worldwide. Microbial conversion of glyphosate to CO2 and biogenic non-extractable residues (bioNER) leads to its complete degradation. The degradation of glyphosate may vary in different soils and it depends on environmental conditions and soil properties. To date, the influence of temperature, soil pH and total organic carbon (TOC) on microbial conversion of glyphosate to bioNER has not been investigated yet. The pH or TOC of an agricultural original soil (pH 6.6, TOC 2.1%) was modified using sulfuric acid or farmyard manure (FYM), respectively. Each treatment: original (I), 3% TOC (II), 4% TOC (III), pH 6.0 (IV) and pH 5.5 (V) was amended with ¹³C3¹⁵N-glyphosate and incubated at 10 °C, 20 °C and 30 °C for 39 days. The temperature was the main factor controlling the mineralization and the extractable ¹³C3¹⁵N-glyphosate, whereas higher TOC content and lower pH resulted in enhanced formation of ¹³C-bioNER. After 39 days the cumulative mineralization of ¹³C-glyphosate was in the range of 12–22% (10 °C), 37–47% (20 °C) and 43–54% (30 °C). Extractable residues of ¹³C-glyphosate were in the range of 10–21% (10 °C) and 4–10% (20 °C and 30 °C); whereas those of ¹⁵N-glyphosate were as follows 20–32% (10 °C) and 12–25% (20 °C and 30 °C). The ¹³C-NER comprised about 53–69% of ¹³C-mass balance in soils incubated at 10 °C, but 40–50% in soils incubated at 20 °C and 30 °C. The ¹⁵N-NER were higher than the ¹³C-NER and varied between 62% and 74% at 10 °C, between 53% and 81% at 20 °C and 30 °C. A major formation of ¹³C-bioNER (72–88% of ¹³C-NER) at 20 °C and 30 °C was noted in soil amended with FYM. An increased formation of ¹⁵N-bioNER (14–17% of ¹⁵N-NER) was also observed in FYM-amended soil. The xenobiotic ¹⁵N-NER had a major share within the ¹⁵N-NER and thus need to be considered when assessing the environmental risk of glyphosate-NER.
... A methanol:-water gradient was used (with the mobile phases previously conditioned with 5 mM ammonium acetate) at 0.5 mL·min −1 . As described in Meyer et al. (2009), selected-ion monitoring in the negative-ionization mode was applied for detection of GLP-FMOC, [ 13 C, 15 N]GLP-FMOC, and AMPA-FMOC. The quantification of both ATZ and [ 5 D]ATZ was conducted in the isocratic mode with 0.1% (v/v) formic acid in acetonitrile/water (70/30) as the mobile phase and same column as used for the GLP analysis. ...
The presence in the atmosphere of glyphosate (GLP) and atrazine (ATZ) was investigated-those pesticides dominating the market in Argentina-through rain, as the main climatic phenomenon associated with wet deposition, both through analyzing source-receptor relationships with soil along with the climatic influences that may condition that transport and through estimating the annual deposition on the surface of the Argentine pampas. Rainwater samples (n = 112) were collected throughout each rainfall in urban areas of the pampas having different degrees of land use and with extensive crop production plus subsurface-soil samples (n = 58) from the relevant periurban sites. The herbicides-analyzed by liquid-chromatography-mass-spectrometry-were detected in >80% of the rain samples at median-to-maximum concentrations of 1.24-67.3 μg·L-1 (GLP) and 0.22-26.9 μg·L-1(ATZ), while aminomethylphosphonic acid (AMPA) was detected at 34% (0.75-7.91 μg·L-1). In soils, GLP was more frequently registered (41%; 102-323 μg·kg-1) followed by ATZ (32%; 7-66 μg·kg-1) and then AMPA (22%; 223-732 μg·kg-1). The maximum GLP concentrations quantified in rainwater exceeded the previously reported levels for the USA and Canada. No associations were observed between soil and rainwater concentrations in the same monitoring areas-despite the soil's action as a source, as evidenced through the AMPA present in rainwater. Median GLP concentrations were significantly associated with isohyets, in an increasing gradient from the east to the west-as such in an inverse pattern to that of the annual rainfall volumes; whereas ATZ-rainwater levels exhibited no characteristic spatial configuration. The estimated annual deposition of GLP by rainfall indicated that more than onc source of a herbicide can lead to its presence in the atmosphere and points out the relevance of rainfall's contribution to the surface levels of a pollutant.
... Although results are not presented in the present study, selected weekly samples collected at 27 sites (160 samples) also were analyzed for glyphosate by LC-MS/MS at the USGS Organic Geochemistry Research Laboratory in Lawrence, KS (Meyer et al., 2009). The methods, results, and a comparison between the ELISA and LC-MS/MS methods are published elsewhere (Mahler et al., 2016). ...
... Glyphosate was analyzed separately by enzyme-linked immunoassay (ELISA) at the USGS Texas Water Science Center in Austin, TX, at an MRL of 200 ng/L . To confirm the ELISA results, a subset (20%) of the samples was analyzed for glyphosate by LC-MS/ MS at the USGS Kansas Water Science Center in Lawrence, KS, with an MRL of 20 ng/L (Meyer et al., 2009). There was good agreement between the concentrations measured and the temporal patterns described by the two methods . ...
Aquatic organisms in streams are exposed to pesticide mixtures that vary in composition over time in response to changes in flow conditions, pesticide inputs to the stream, and pesticide fate and degradation within the stream. To characterize mixtures of dissolved-phase pesticides and degradates in Midwestern streams, a synoptic study was conducted at 100 streams during May–August 2013. In weekly water samples, 94 pesticides and 89 degradates were detected, with a median of 25 compounds detected per sample and 54 detected per site. In a screening-level assessment using aquatic-life benchmarks and the Pesticide Toxicity Index (PTI), potential effects on fish were unlikely in most streams. For invertebrates, potential chronic toxicity was predicted in 53% of streams, punctuated in 12% of streams by acutely toxic exposures. For aquatic plants, acute but likely reversible effects on biomass were predicted in 75% of streams, with potential longer-term effects on plant communities in 9% of streams. Relatively few pesticides in water—atrazine, acetochlor, metolachlor, imidacloprid, fipronil, organophosphate insecticides, and carbendazim—were predicted to be major contributors to potential toxicity. Agricultural streams had the highest potential for effects on plants, especially in May–June, corresponding to high spring-flush herbicide concentrations. Urban streams had higher detection frequencies and concentrations of insecticides and most fungicides than in agricultural streams, and higher potential for invertebrate toxicity, which peaked during July–August. Toxicity-screening predictions for invertebrates were supported by quantile regressions showing significant associations for the Benthic Invertebrate-PTI and imidacloprid concentrations with invertebrate community metrics for MSQA streams, and by mesocosm toxicity testing with imidacloprid showing effects on invertebrate communities at environmentally relevant concentrations. This study documents the most complex pesticide mixtures yet reported in discrete water samples in the U.S. and, using multiple lines of evidence, predicts that pesticides were potentially toxic to nontarget aquatic life in about half of the sampled streams.
