Metabolites In Surface Waters Research Articles

Identification of ionic chloroacetanilide-herbicide metabolites in surface water and groundwater by HPLC/MS using negative ion spray.

Solid-phase extraction (SPE) was combined with high-performance liquid chromatography/high-flow pneumatically assisted electrospray mass spectrometry (HPLC/ ESP/MS) for the trace analysis of oxanilic and sulfonic acids of acetochlor, alachlor, and metolachlor. The isolation procedure separated the chloroacetanilide metabolites from the parent herbicides during the elution from C18 cartridges using ethyl acetate for parent compounds, followed by methanol for the anionic metabolites. The metabolites were separated chromatographically using reversed-phase HPLC and analyzed by negative-ion MS using electrospray ionization in selected ion mode. Quantitation limits were 0.01 microgram/L for both the oxanilic and sulfonic acids based on a 100-mL water sample. This combination of methods represents an important advance in environmental analysis of chloroacetanilide-herbicide metabolites in surface water and groundwater for two reasons. First, anionic chloroacetanilide metabolites are a major class of degradation products that are readily leached to groundwater in agricultural areas. Second, anionic metabolites, which are not able to be analyzed by conventional methods such as liquid extraction and gas chromatography/mass spectrometry, are effectively analyzed by SPE and high-flow pneumatically assisted electrospray mass spectrometry. This paper reports the first HPLC/MS identification of these metabolites in surface water and groundwater.

Diuron and Its Metabolites in Surface Water and Ground Water by Solid Phase Extraction and In-Vial Elution

A simple and rapid method was developed to determine concentrations of diuron [N‘-(3,4-dichlorophenyl)-N,N-dimethylurea] and three of its major metabolites, N‘-(3,4-dichlorophenyl)-N-methylurea (DC...

Alachlor and its metabolites in surface water

Biodegradation of alachlor in water was tested in different experimental conditions. This compound is rather persistent since its degradation is lower than 50 % after 28 d of incubation. The highest biodegradation extent was observed at very low concentrations, like those measured in field, or when alachlor is the primary carbon source. About 20 breakdown products were detected and three of them were confirmed by comparison with pure commercial compounds: 2,6-diethylaniline (DEA) and 2′,6′-diethyl-N-2-hydroxy(methoxymethyl) acetanilide (hydroxy-alachlor). DEA was found in Italian surface waters polluted by alachlor. This compound arises concern because it has a high mobility in soil and is a precursor of mutagenic compounds in mammal metabolism.

A reconnaissance study of herbicides and their metabolites in surface water of the midwestern United States using immunoassay and gas chromatography/mass spectrometry

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA reconnaissance study of herbicides and their metabolites in surface water of the midwestern United States using immunoassay and gas chromatography/mass spectrometryE. Michael Thurman, Donald A. Goolsby, Michael T. Meyer, Margaret S. Mills, Michael L. Pomes, and Dana W. KolpinCite this: Environ. Sci. Technol. 1992, 26, 12, 2440–2447Publication Date (Print):December 1, 1992Publication History Published online1 May 2002Published inissue 1 December 1992https://doi.org/10.1021/es00036a016RIGHTS & PERMISSIONSArticle Views735Altmetric-Citations294LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts Get e-Alerts

Low ng/1-level determination of twenty N-methylcarbamate pesticides and twelve of their polar metabolites in surface water via off-line solid-phase extraction and high-performance liquid chromatography with post-column reaction and fluorescence detection

Reversed-phase high-performance liquid chromatography (HPLC) was used for the determination of twenty parent N-methylcarbamate pesticides and twelve major metabolites in surface water. A 50-ml water sample was passed through a disposable solid-phase extraction cartridge, packed with 500 mg of low-carbon C 18-bonded silica (C 18/OH, 40 μm particle size), which selectively retained polar compounds. The preconcentrated analytes were eluted with acetonitrile, reconstituted in 1 ml of water and 100 μl were injected into the HPLC system. The carbamates were separated via a water-methanol-acetonitrile gradient. Detection was performed via postcolumn hydrolysis on a solid-phase (anion-exchange) catalyst, derivatization of the methylamine formed with o-phthalaldehyde-2-mercaptoethanol and fluorescence detection of the isoindole derivative. The detection limits for surface water were between 20 and 30 ng/l. Recoveries were determined for thirteen carbamates and ten metabolites at the 0.1 and 1 μg/1 level and generally ranged from 76 to 106% with relative standard deviations (R.S.D.s) of 0.5–8.5%. Only the sulphoxide metabolite of ethiofencarb and thiofanox had lower recoveries and correspondingly higher R.S.D.s.