Chloroacetanilide herbicides water

Analytical methods for parent chloroacetanilide herbicides in soil typically involve extraction of the soil with solvent, followed by solid-phase extraction (SPE), and analysis by gas chromatography/electron capture detection (GC/ECD) or gas chromatog-raphy/mass spectrometry (GC/MS). Analytical methods for parent chloroacetanilides in water are similarly based on extraction followed by GC with various detection techniques. Many of the water methods, such as the Environmental Protection Agency (EPA) official methods, are multi-residue methods that include other compound classes in addition to chloroacetanilides. While liquid-liquid partitioning was used initially to extract acetanilides from water samples, SPE using... 

This study will provide fundamental information on the effect of stereoisomerism on the environmental fate of a widely used chloroacetanilide herbicide, metolachlor. Metolachlor is classified as a potential carcinogen and is the second most extensively used herbicide in the United States (7). Biological dechlorination of metolachlor leads to the formation of more polar metabolites (8), metolachlor oxanilic acid (OXA), and metolachlor ethanesulfonic acid (ESA) (Figure 3). Metolachlor OXA and metolachlor ESA are found at higher concentrations and are more frequently detected in surface and ground water than their parent compound (9). 

Ferrer, I., E.M. Thurman, and D. Barcelo (1997). Identification of ionic chloroacetanilide-herbicide metabolites in surface water and groundwater by HPLC/MS using negative ion spray. Anal. Chem., 69 4547-4553. 

Kish, J.L., E.M. Thurman, E.A. Scribner, and L.R. Zimmerman (2000). Method of analysis by the US Geological Survey Organic Geochemistry Research Group Determination of triazine and chloroacetanilide herbicides in water by solid-phase extraction and capillary column gas chromatography/mass spectrometry with selected ion monitoring USGS Open-File Report 00-385. 

In conclusion, our results demonstrate an effective application of polyclonal antibodies directed toward alachlor. These antibodies were used to develop an ELISA with a detection range from 0.2 to 8.0 ppb for alachlor in water. The demonstrated ability of the antibodies to distinguish alachlor from other chloroacetanilide herbicides allowed the successful application of this assay to the analysis of environmental water samples. Based on the analysis of a limited number of environmental water samples, the ELISA method was shown to be less accurate and precise than GC/MS. On the other hand, ELISA offers considerable advantages over GC/MS in terms of cost, speed, sample throughput, and portability. Our results suggest that the most effective use of this ELISA would be as a primary screen, in which samples falling below a threshold level of alachlor can be rapidly and cost-effectively eliminated from further instrumental analysis. 

KaUdioff, S. J., Kolpin, D. W., Thurman, E. M., Eerrer, I., and Barcelo, D., Degradation of chloroacetanilide herbicides the prevalence of sulfonic and oxanilic acid metabolites in Iowa groundwater and surface water, Environ. Set TechnoL, 32, 1738-1740, 1998. 

Hostetler, K. A. and Thurman, E. M., Determination of chloroacetanilide herbicide metabolites in water using high performance liquid chromatography diode array detection and high performance liquid chromatography mass spectrometry. Set Total Environ., 248, 147-156, 2000. 

An extensive body of literature has been published with respect to the quantitative analysis of TPs of pesticides in air [27,28], surface waters [29,30], groundwater [31,32], sediment [33,34], and soil [35,36] and several critical reviews on existing methods have been recently pubhshed [37,38]. A number of multiresidue methods have been developed for the determination of parent compounds and TPs covering a wide range of pesticide classes [37]. Compounds that are typically included into monitoring programmes are organochlorines DDT and its TPs DDE and DDD endosul-fan, endrin, and heptachlor and their TPs triazine herbicide atrazine and its TPs deethylatrazine and deisopropylatrazine chloroacetanilide herbicides and their acidic TPs. 

Chloroacetanilides are soil-applied herbicides used for pre- and early post-emergence control of annual grasses and broadleaf weeds in crops. Representative chloroacetanilide compounds, alachlor, acetochlor, and metolachlor, are extensively used worldwide. Other chloroacetanilides with limited usages include propachlor, bu-tachlor, metazachlor, pretilachlor, and thenylchlor. Public environmental concerns and government regulatory requirements continue to prompt the need for reliable methods to determine residues of these herbicides. There now exist a variety of analytical methods to determine residues of these compounds in crops, animal products, soil, and water. The chemical structures and major crops in which these compounds are used are summarized in Table 1. 

Analysis of pesticides in water was performed by fully automated online solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/ MS) [25, 31]. These pesticides (a total of 22 belonging to the classes of triazines, OP, chloroacetanilides, phenylureas, thiocarbamates, acid herbicides, and anilides) were selected on the basis of previously published studies [20, 25], information gathered from the water authorities, and known use in rice crops. 

Measurement of Chloroacetanilide and Chloroacetamide Herbicide Degradates in Drinking Water by SPE and... 

J.D. Vargo, Determination of chloroacetanilide and chloroacetamide herbicides and their polar degradation products in water by LC/MS/MS. In Liquid Chromatography/Mass Spectrometry, MS/MS and Time of Flight MS Analysis of Emerging Contaminants, I. Ferrer, E.M. Thurman (Eds.), American Chemical Society, Washington, DC, 2003. 

Some recent surveys in the Mississippi River basin pointed out the importance of chloroacetanilide metabolites in surface water. Thus, sulfonic acid and oxanilic acid (OXA) averaged 70% of the total herbicide concentration in samples from the upper Mississippi River, whereas this proportion was much less in the Missouri and Ohio Rivers, 24% and 41%, respectively. ... 

Chloroacetanilides and nitrogen heterocyclic herbicides Soil (5 g) PFE Pretreatment with 31.6% of water. 32 ml acetone, 1500 psi, 100°C Dried over Na2S04, filtered, evaporated to 1 ml, and adjusted to 5 ml with MTBE 93 to 103 1 to 7 GC-MS 2000 196... 

There are fewer applications of PEE to the extraction of herbicides in soils,being mainly used until now for PAH and PCB extractions. Guzella and Pozzoni performed one of the first successful studies with PEE, by comparing it with Soxhlet procedures on triazine and chloroacetanilide extractions from agricultural soils.A PEE method was developed to extract metribuzin and three metabolites (deaminometribuzin, deaminodiketometribuzin, and diketometribuzin) with methanol-water (75 25) at 60°C. Recoveries were about 75% with detection limits of 1 ng/g, except for diketometribuzin with only 50% of recovery and detection limit higher than 10 ng/g. ... 

Systematic investigation of pesticides in the Chesapeake Bay watershed began in the 1970 s in response to the observed decline in SAV and fish populations during that period. Investigations typically spanned a few years and tested for specific families of herbicides (e.g., dUoro-s-triazines and chloroacetanilides) and insecticides (e.g., organophosphates and chlorinated hydrocarbons) in various media. Detection limits and consistency in the methods of data collection improved with time. The data that are sununarized below consist of measurements of concentrations of atrazine in the iiqruts to surface waters at several locations throughout the Bay. We should stress that data are sparse spatial and temporal distributions have to be estimated and/or extrapolated from measurements in the top 0.5-1.0 m of the surface layer. 

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