Sulfonylureas surface water

Only a few models applicable to paddy field conditions have been developed. RICEWQ by Williams, PADDY by Inao and Kitamura," and PCPF-1 by Watanabe and Takagi are useful for paddy fields. EXAMS2 by the United States Environmental Protection Agency (USEPA), a surface water model, can also be used to simulate paddy fields with an appropriate model scenario and has been used for the prediction of sulfonylurea herbicide behavior in paddy fields. The prediction accuracy of PADDY and PCPF-1 is high, although these models require less parameter... 

M. Rodriguez and D.B. Orescan, Confirmation and quantitation of selected sulfonylurea, imida-zolinone, and sulfonamide herbicides in surface water using electrospray LC/MS, Anal. Chem., 70, 2710-2717 (1998). 

ESI, triazines) [537]. Recoveries observed were > 80% except for carbendazim, bu-tocarboxim, aldicarb and molinate, all better than 67% [500]. An aoTOF-MS interfaced by ESI was used to screen and identify unknown compounds and pesticides in water samples by MS and MS/MS. Structures for compounds observed besides pesticides were proposed [538]. Traces of the phenylurea pesticides Hnuron and monolinuron in water were determined quantitatively. Calibration graphs obtained after Supelclean ENVI-18 SEE were Hnear with detection limits < 25 pg [511]. Large numbers of phenylurea herbicide analyses led to the elaboration of on-line preconcentration techniques coupled to ESI-LC-MS. The procedure was demonstrated and validated with several pesticides using 10 ml of sample, resulting in detection Hmits of about 10 ng [539]. ESI-LC-MS and MS/MS were applied to quantify and to confirm 16 different herbicides of sulfonylurea [527] type in surface water samples. Surface water samples were extracted by SPE (Spe-ed RP-102). As confirmation criteria RT, molecular ion and two fragment ions besides ion abundance ratios were defined. Quantitation at 0.1 and 1.0 ppb level was demonstrated [540]. 

A single multiresidue method was developed to determine 109 priority compoimds listed in the 76/464/EEC Coimcil Directive on Pollution of the EU [49]. For trapping analytes, automated off-line SPE with a polymeric sorbent "Oasis" 60 mg cartridge, was optimized. A multianalyte method for the confirmation and quantitation of 16 selected sulfonylurea, imidazolinone, and sulfonamide herbicides in surface water has been proposed [50]. This method is based on analyte extraction with a polymeric material (RP-102) and extract cleanup with a strong anion exchanger (SAX) cartridge stacked on... 

Plan of Study to Determine the Occurrence of Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides in Surface and Ground-Water of the Midwestern United States. US Geological Survey, Washington, DC (1998). Also available on the World Wide Web http //webserver.cr.usgs.gov/midconherh/html/workplan98.html, accessed September 2002. 

Volmer et al. studied phenylureas and sulfonylureas by TSP-LC-MS after sample concentration by Cjg SPE [175]. 15 phenylurea- and 1 thiourea pesticides besides 112 polar pesticides from other pesticide classes were examined by TSP ionisation, detection limits and TSP mass spectra of these polar compounds were presented [245], Besides other polar pesticides, the phenylurea pesticides isoproturon and diuron were on-line concentrated on a precolumn from several surface and drinking water samples and then determined by TSP-LC-MS [247]. A multi-residue TSP-LC-MS method was published by Moore et al. for the determination of the urea pesticides chlortoluron, diuron, isoproturon, and Unuron in water samples after Cig-SPE [248]. Ci8 Empore disks were applied to concentrate phenylureas from river water and spiked seawater samples prior to TSP-LC-MS. Detection limits of 2-20 (ig L and recoveries between 80 and 125% were observed [239]. TSP-LC-MS (SIM) in the positive mode allowed determination of the urea pesticides chlor-bromuron, diuron, linuron, metobromuron, monuron, neburon in apples, beans, lettuce, peppers, potatoes and tomatoes with detection limits of 0.025-1 ppm [255]. 20 other polar pesticides, linuron, which was under suspicion of being a dietary oncogenic risk (US Natl. Res. Council) was determined by TSP-LC-MS a single rapid procedure in vegetables with detection limits of 0.05-0.10 ppm [270]. TSP-LC-MS and ESI were used in a multi-residue method for determination of the sul-... 

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