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W T - One of the best experts on this subject based on the ideXlab platform.
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gas chromatography ion trap mass spectrometry applied for the analysis of triazine herbicides in environmental waters by an isotope dilution technique
Analytica Chimica Acta, 2004Co-Authors: Dongli Wang, W TAbstract:Abstract A gas chromatography/ion trap mass spectrometry method was developed for the analysis of simazine, atrazine, cyanazine, as well as the degradation products of atrazine, such as Deethylatrazine and deisopropylatrazine in environmental water samples. Isotope dilution technique was applied for the quantitative analysis of atrazine in water at low ng/l levels. One liter of water sample spiked with stable isotope internal standard atrazine-d 5 was extracted with a C 18 solid-phase extraction cartridge. The analysis was performed on an ion trap mass spectrometer operated in MS/MS method. The extraction recoveries were in the range of 83–94% for the triazine herbicides in water at the concentrations of 24, 200, and 1000 ng/l, while poor recoveries were obtained for the degradation products of atrazine. The relative standard deviation (R.S.D.) were within the range of 3.2–16.1%. The detection limits of the method were between 0.75 and 12 ng/l when 1 l of water was analyzed. The method was successfully applied to analyze environmental water samples collected from a reservoir and a river in Hong Kong for atrazine detected at concentrations between 3.4 and 26 ng/l.
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determination of atrazine Deethylatrazine and simazine in water at parts per trillion levels using solid phase extraction and gas chromatography ion trap mass spectrometry
Rapid Communications in Mass Spectrometry, 2003Co-Authors: W T, Zongwei Cai, Guibin JiangAbstract:Methods for trace analysis of atrazine and simazine in water have been developed by using stable-isotope dilution with detection by gas chromatography/mass spectrometry. D-5-Atrazine was used as the internal standard for the determination of atrazine and Deethylatrazine, while C-13(3)-simazine was used for simazine analysis. Water samples were fortified with known amounts of the internal standards and submitted to solid-phase extraction with a C-18 bonded-silica cartridge. A gas chromatograph coupled with an ion-trap mass spectrometer was used to analyze the water sample extracts. Method detection limits were 38 parts-per-trillion (ppt) for atrazine and Deethylatrazine and 75 ppt for simazine. The accuracy of the method, represented by relative analytical errors, was less than 15%, and the method precision was less than 5% (relative standard deviation, n = 9). The method was successfully applied to analyze surface water samples collected from a reservoir and a river at ppt levels. Copyright (C) 2003 John Wiley Sons, Ltd.
Damia Barcelo - One of the best experts on this subject based on the ideXlab platform.
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selective trace enrichment of chlorotriazine pesticides from natural waters and sediment samples using terbuthylazine molecularly imprinted polymers
Analytical Chemistry, 2000Co-Authors: Francesca Lanza, Antal Tolokan, Viola Horvath, George Horvai, Börje Sellergren, Imma Ferrer, Damia BarceloAbstract:Two molecularly imprinted polymers were synthesized using either dichloromethane or toluene as the porogen and terbuthylazine as the template and were used as solid-phase extraction cartridges for the enrichment of six chlorotriazines (deisopropylatrazine, Deethylatrazine, simazine, atrazine, propazine, and terbuthylazine) in natural water and sediment samples. The extracted samples were analyzed by liquid chromatography/diode array detection (LC/DAD). Several washing solvents, as well as different volumes, were tested for their ability to remove the matrix components nonspecifically adsorbed on the sorbents. This cleanup step was shown to be of prime importance to the successful extraction of the pesticides from the aqueous samples. The optimal analytical conditions were obtained when the MIP imprinted using dichloromethane was the sorbent, 2 mL of dichloromethane was used in the washing step, and the preconcentrated analytes were eluted with 8 mL of methanol. The recoveries were higher than 80% for all ...
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monitoring of priority pesticides and other organic pollutants in river water from portugal by gas chromatography mass spectrometry and liquid chromatography atmospheric pressure chemical ionization mass spectrometry
Journal of Chromatography A, 2000Co-Authors: Silvia Lacorte, Debora A Azevedo, Tereza Vinhas, Paula Viana, Damia BarceloAbstract:Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS) were optimized and applied for the trace-level determination of 42 priority pesticides and 33 priority organic pollutants from European Union Directive EC 76/464. First, off-line solid-phase extraction of 200 ml of river water using an OASIS solid-phase extraction cartridge, followed by GC-MS was used. Next, selected samples that were positive to GC-MS were analyzed by LC-APCI-MS in order to detect further polar byproducts or to improve the determination of previously detected polar analytes. The transformation products of triazine pesticides like Deethylatrazine (DEA) and deisopropylatrazine (DIA) and compounds such as diuron and several chlorophenols were positively identified by LC-APCI-MS. The present methodology has also been used for searching for new analytes not included in the EC 76/464 list, like Irgarol, DEA and DIA. In addition it was applied to target pollutants in 43 river water samples from Portugal during a pilot survey from April to July 1999. Atrazine followed by simazine and 2,4,6-trichlorophenol were the most ubiquitous compounds detected in this area. The levels detected of the different compounds were in the range of: 0.01-2.73 microg/l, 0.05-0.74 microg/l, 0.02-1.65 microg/l, 0.02-5.43 microg/l, 0.01-0.40 microg/l, 0.01-0.26 microg/l, 0.02-0.61 microg/l, 0.01-3.90 microg/l, 0.01-1.24 microg/l, 0.02-2.3 microg/l, 0.01-0.13 microg/l and 0.01-0.5 microg/l for atrazine, simazine, terbuthylazine, alachlor, metolachlor, Irgarol, propanil; tributhylphosphate, diuron, 2,4,6-trichlorophenol, deisopropylatrazine and Deethylatrazine, respectively.
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determination of atrazine and alachlor in natural waters by a rapid magnetic particle based elisa influence of common cross reactants Deethylatrazine deisopropylatrazine simazine and metolachlor
Analytica Chimica Acta, 1995Co-Authors: J Gascon, E Martinez, Damia BarceloAbstract:Abstract The determination of atrazine and alachlor in various water types (distilled, ground and estuarine waters) in the presence of the common interfering compounds Deethylatrazine, deisopropylatrazine and simazine (atrazine) and metolachlor (alachlor) has been investigated using direct rapid-magnetic particle-based ELISA. The interferences were studied at a fixed concentration of 0.5 μg l−1 atrazine or alachlor and at varying concentrations of the cross-reactants from 0.05 to 5 μg 1−1. Cross-reactivity values varied from 65–81% to 1.1% for Deethylatrazine and metolachlor, respectively. Recommendations about the applications of the ELISA test to different types of water samples are given.
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confirmation of chlorotriazine pesticides their degradation products and organophosphorus pesticides in soil samples using gas chromatography mass spectrometry with electron impact and positive and negative ion chemical ionization
Analytica Chimica Acta, 1991Co-Authors: G Durand, Damia BarceloAbstract:Gas chromatography-mass spectrometry (GC-MS) with electron impact (EI), positive-ion chemical ionization (PCI) and negative-ion chemical ionization (NCI) were applied as confirmatory techniques for residue analysis of chlorotriazine pesticides, their degradation products and organophosphorus pesticides in soil samples. Clean-up was effected using a Florisil column with subsequent analysis by GC with a nitrogen-phosphorus detector. GC-MS with the EI mode of operation is the common mode of confirmation for all the pesticides. Further confirmation by either GC-MS with PCI and NCI for chlorotriazines and organophosphorus pesticides, respectively, is recommended. The method was applied to the determination of residue levels of atrazine, Deethylatrazine, deisopropylatrazine, simazine, fenitrothion and tetrachlorvinphos in several soil samples at levels from 5 ng g−1 to 9 μg g−1.
Guibin Jiang - One of the best experts on this subject based on the ideXlab platform.
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determination of atrazine and its deethylated degradation product in water and sediment by using gas chromatography ion trap mass spectrometry
International Journal of Environmental Analytical Chemistry, 2005Co-Authors: Wai Tang, Guibin Jiang, Zongwei CaiAbstract:A gas chromatography/ion trap mass spectrometry method was used for the trace analysis of atrazine and its deethylated degradation product Deethylatrazine in environmental water and sediment samples. The isotope dilution technique was applied for the quantitative analysis of atrazine at parts-per-trillion levels. Water samples were pre-concentrated by solid-phase extraction using a C18 cartridge while the sediment samples were extracted by sonication with methanol. The concentrated extracts were analysed by a GC/ion trap MS operated in the MS/MS method. The extraction recoveries for the analytes were better than 83% when 1 L of water or 10 g of sediment was analysed. The method detection limits were 0.75 ng/L and 0.13 ng/g for atrazine and Deethylatrazine detected in water and sediment, respectively. The precisions of the method represented by the relative standard deviation were in the range of 3.2-16.1%. The method was successfully applied to analyse surface water and sediment samples collected from Bei...
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determination of atrazine Deethylatrazine and simazine in water at parts per trillion levels using solid phase extraction and gas chromatography ion trap mass spectrometry
Rapid Communications in Mass Spectrometry, 2003Co-Authors: W T, Zongwei Cai, Guibin JiangAbstract:Methods for trace analysis of atrazine and simazine in water have been developed by using stable-isotope dilution with detection by gas chromatography/mass spectrometry. D-5-Atrazine was used as the internal standard for the determination of atrazine and Deethylatrazine, while C-13(3)-simazine was used for simazine analysis. Water samples were fortified with known amounts of the internal standards and submitted to solid-phase extraction with a C-18 bonded-silica cartridge. A gas chromatograph coupled with an ion-trap mass spectrometer was used to analyze the water sample extracts. Method detection limits were 38 parts-per-trillion (ppt) for atrazine and Deethylatrazine and 75 ppt for simazine. The accuracy of the method, represented by relative analytical errors, was less than 15%, and the method precision was less than 5% (relative standard deviation, n = 9). The method was successfully applied to analyze surface water samples collected from a reservoir and a river at ppt levels. Copyright (C) 2003 John Wiley Sons, Ltd.
Jorge C. Masini - One of the best experts on this subject based on the ideXlab platform.
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Online Sequential-Injection Chromatography with Stepwise Gradient Elution: A Tool for Studying the Simultaneous Adsorption of Herbicides on Soil and Soil Components
2013Co-Authors: Ricardo De Prá Urio, Carlos M.c. Infante, Jorge C. MasiniAbstract:The adsorption of triazine herbicides simazine (SIM), atrazine (ATR), and propazine (PRO) as well as the metabolites deisopropylatrazine (DIA), Deethylatrazine (DEA), and 2-hydroxyatrazine (HAT) on soil, humic acid, and soil modified with humic acidic was studied by sequential-injection chromatography with UV detection at 223 nm. An online monitoring system was assembled, which was composed of a tangential filter and a peristaltic pump for the circulation of the soil (25 g L–1) or humic acid (2.5 g L–1) suspensions. A stepwise gradient elution separated the compounds using three mobile phases whose compositions were 28, 40, and 50% (v v–1) methanol in 1.25 mmol L–1 ammonium acetate buffer, pH 4.7. The sampling throughput was about six analyses per hour; the linear dynamic range was between 100 and 1000 μg L–1 for all of the studied compounds. The detection limits varied from 9 μg L–1 for ATR to 36 μg L–1 for DEA. At contact times
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montmorillonite as an adsorbent for extraction and concentration of atrazine propazine Deethylatrazine deisopropylatrazine and hydroxyatrazine
Analytica Chimica Acta, 2006Co-Authors: Lilian Zarpon, Gilberto Abate, Luciana Dos B O Santos, Jorge C. MasiniAbstract:Abstract Adsorption properties of the clay mineral montmorillonite in the potassium homoionic form (KMT) was investigated to achieve the extraction and concentration of the herbicides atrazine (AT) and propazine (PROP), as well as the main degradation products of atrazine, namely Deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (ATOH). A batch approach was proposed, with recovery percentages for AT, PROP and DIA higher than 90% at concentrations of 0.50 and 2.50 μg L −1 . For DEA and ATOH, however, low recoveries were obtained. For DEA, this fact can be explained by its low K d with KMT, contrary to ATOH, which interacts strongly with the mineral surface, hindering the complete desorption and hence, generating low recovery percentages. The influence of pH, ionic strength and humic acid was studied, and a comparison with the C 18 phase as SPE cartridges was carried out. Montmorillonite showed a similar performance to commercial cartridge for concentrations of AT, DEA and PROP, but better recoveries for DIA was obtained using the clay mineral. For ATOH the recovery was also higher on the clay mineral, although for this compound the most suitable SPE cartridge is constituted by cation exchange resin. After the concentration and elution steps, the 0.50 and 2.50 μg L −1 gave chromatographic peak areas that could be easily quantified with an analytical curve obtained in the concentration range between 7.5 and 100 μg L −1 . The obtained concentration factors are suitable to allow the application of the method to the monitoring of triazine residues in drinking water.
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sorption of atrazine propazine Deethylatrazine deisopropylatrazine and hydroxyatrazine onto organovermiculite
Journal of the Brazilian Chemical Society, 2005Co-Authors: Gilberto Abate, Jorge C. MasiniAbstract:The interaction of atrazine (AT), propazine (PROP), Deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HAT) was studied with the clay mineral vermiculite saturated with K+ (VTK), and with the mineral modified by insertion of hexadecyltrimethyl-ammonium (HDTMA-VT) in the interlayer of VTK. The crude VTK exhibited negligible interaction with AT, PROP and DEA, moderate interaction with DIA and strong interaction with HAT. For the HDTMA-VT materials, removal percentages from aqueous medium for initial concentrations between 0.05 and 1.00 mg L-1 were 56 to 63% for AT, 43 to 45% for DEA, 12 to 19% for HAT and 77 to 78% for PROP. Sorption of AT, DEA and PROP onto HDTMA-VT was significantly enhanced in comparison to VTK. Ionic strength and pH had no significant influence on the sorption process. Desorption of all compounds from HDTMA-VT after 24 h of contact time was between 20 and 30% of the amount initially adsorbed.
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adsorption of atrazine hydroxyatrazine Deethylatrazine and deisopropylatrazine onto fe iii polyhydroxy cations intercalated vermiculite and montmorillonite
Journal of Agricultural and Food Chemistry, 2005Co-Authors: Gilberto Abate, Jorge C. MasiniAbstract:This paper describes the modification of the clay minerals vermiculite (VT) and montmorillonite (MT) by intercalating Fe(III) polymers of different [OH(-)]:[Fe(III)] ratios with the aim of removing atrazine (AT) and its metabolites Deethylatrazine (DEA), deisopropylatrazine (DIA), and hydroxyatrazine (ATOH) from aqueous solution. An enhancement of adsorption capacity was observed for both intercalated clay minerals in comparison to the potassium-saturated materials (KVT or KMT). The results showed that different [OH(-)]:[Fe(III)] molar ratios had a small influence on the adsorption capacity, as well as in the basal spacing, BET surface area, and porosity. For the lowest initial concentrations of AT, DIA, and ATOH (0.050 mg L(-)(1)) studied, the modified VT adsorbed almost 80% of AT and DIA, while ATOH was removed at concentration levels below the detection limit of the technique, implying in at least 99.5% of sorption. Weak interaction between intercalated VT and DEA was observed, although a significant adsorption enhancement occurred in comparison to KVT. Within a 24 h interval, desorption of AT and DIA in aqueous medium reached levels close to 20% of the amount initially adsorbed, while for ATOH only 3% of the adsorbed compound was desorbed. The adsorption capacity of the Fe(III)-intercalated VT decreased after the first adsorption/desorption cycle, implying that the material is not suitable for reutilization. The intercalated MT was a powerful sorbent for AT, DEA, DIA, and ATOH, removing all of these chemicals from solution almost quantitatively (sorption greater than 99.5%), even at initial concentrations as high as 1.0 mg L(-)(1). Additionally, desorption of AT, ATOH, and DIA in water was not measurable up to the tube corresponding to the initial concentration of 1.0 mg L(-)(1), suggesting strong irreversible binding of these compounds to the intercalated MT materials. Desorption of DEA from the intercalated MT was between 5 and 30%. Unlike what was observed for VT, the intercalated MT materials were recyclable, keeping an excellent performance when reutilized.
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influence of humic acid on adsorption and desorption of atrazine hydroxyatrazine Deethylatrazine and deisopropylatrazine onto a clay rich soil sample
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Gilberto Abate, Jose Carlos P Penteado, Jonas D Cuzzi, Godofredo Cesar Vitti, Jaim Lichtig, Jorge C. MasiniAbstract:Adsorption and desorption properties of atrazine and some of its metabolites, hydroxyatrazine (AT-OH), Deethylatrazine (DEA), and deisopropylatrazine (DIA), were studied with a clay-rich soil sample (clay content of 53%). A part of this soil was treated with humic acid (Soil-HA) to assess the influence of this important component of natural organic matter on adsorption and desorption processes. This study was performed using the batch approach with 1.0 g of soil, or Soil-HA, in 5.0 mL of 0.010 mol L-1 CaCl2 solution containing the herbicide and the metabolites in a concentration range between 0.010 and 5.0 mg L-1. After 24 h of contact time, the suspensions were centrifuged and the four compounds were quantified in the supernatant phases by high-performance liquid chromatography. The adsorption and desorption data of both Soil and Soil-HA were properly fitted by the linearized Freundlich equation. For the untreated soil, the adsorption affinity order evaluated as a function of the Kf values was AT-OH > AT...
Joel R Coats - One of the best experts on this subject based on the ideXlab platform.
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enhanced degradation of Deethylatrazine in an atrazine history soil of iowa
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes, 1997Co-Authors: Ellen L Arthur, Jennifer C Anhalt, Todd A Anderson, Joel R CoatsAbstract:Abstract The degradation of Deethylatrazine (DEA), a major metabolite of atrazine, was studied by using radiotracers in soils with two different atrazine histories. DEA degradation was enhanced in soils which had received long‐term exposure to atrazine (atrazine‐history soil) compared with soils that had not received long‐term atrazine exposure (no‐history soil). After 60 days of incubation, mineralization of DEA to 14CO2 in the atrazine‐history surface soil was twice that in the no‐history surface soils, with 34% and 17% of the applied 14C‐DEA as CO2, respectively. In surface soils, 25% of the applied 14C remained as DEA in the atrazine‐history soil, compared with 35% in the no‐history soil. Microbial plate counts indicated an increase in numbers of bacteria and fungi in soils incubated with DEA compared to control soils. No significant difference in total microbial respiration was seen among atrazine‐history and no‐history soils incubated with DEA, but DEA‐treated soils had greater microbial respiration...
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comparative fates of atrazine and Deethylatrazine in sterile and nonsterile soils
Journal of Environmental Quality, 1997Co-Authors: Ellen L Kruger, Pamela J Rice, Jennifer C Anhalt, Todd A Anderson, Joel R CoatsAbstract:Assessment of biotic and abiotic mechanisms of atrazine (ATR) and Deethylatrazine (DEA) breakdown is necessary to identify major degradation patbways and understand soil conditions necessary for these mechanisms to occur. Our purpose was to compare fates of ATR and DEA in laboratory radiotracer studies to elucidate the effects of soil moisture status and soil depth on degradation and persistence. Atrazine and DEA were more persistent in subsurface soil than in surface soil. After 120-d incubation, bound residues were significantly greater in surface soils than in subsurface soils. In 14 C-DEA-treated soil, biological activity contributed to decreased persistence of DEA in saturated surface soil in contrast with unsaturated surface soil after 60 d. Biological activity also contributed to decreased persistence of ATR in saturated subsurface soil in contrast with unsaturated subsurface soil after 120 d, and the decreased persistence corresponded to significantly greater amounts of DEA, deisopropylatrazine (DIA), and polar degradation products compared with other treatments. The percentage of applied 14 C-ATR that degraded to DEA and DIA increased approximately threefold during the 60- to 120-d incubation in nonsterile saturated subsurface soil. Greater quantities of polar degradation products were formed in 14 C-DEA-treated nonsterile compared with sterile soils. Half-lives (from first-order degradation rate constants) of ATR and DEA were significantly longer in subsurface soil compared with surface soils. Biotic mechanisms contributed to the half-lives of ATR (in surface and subsurface soil) and DEA (in subsurface soil) being significantly shorter under saturated soil moisture conditions compared with unsaturated soil moisture conditions.
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Relative mobilities of atrazine, five atrazine degradates, metolachlor, and simazine in soils of iowa
Environmental Toxicology and Chemistry, 1996Co-Authors: Ellen L Kruger, Joel R CoatsAbstract:The relative mobilities of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine), five atrazine degradates, metolachlor (2-chloro-N-[2-ethyl-5-methylphenyl]-N-[2-methoxy-1-methylethyl]-acetamide), and simazine (2-chloro-4,6-bis-[ethylamino]-s-triazine) were determined in both surface and subsurface soils from five locations in Iowa by soil thin-layer chromatography (STLC). Based on mobility of the compounds, four groups were identified from this study. Deethylatrazine (2-chloro-4-amino-6-isopropylamino-s-triazine) was the most mobile compound. The intermediate mobility group included atrazine, deisopropylatrazine (2-chloro-4-ethylamino-6-amino-s-triazine), and didealkylatrazine (2-chloro-4,6-diamino-s-triazine). The less mobile group included metolachlor and simazine, and the nearly immobile group consisted of ammeline (4,6-diamine-s-triazine-2-ol) and hydroxyatrazine (2-hydroxy-4-ethylamino-6-isopropylamino-s-triazine). A clear division between the intermediate and less mobile group was not seen in all soils. Mobilities of all eight compounds in this study were negatively correlated with soil organic matter content (p ≤ 0.05) and positively correlated (except for didealkylatrazine) with sand content (p ≤ 0.05). The greatest degree of mobility for the compounds studied was seen in Fruitland (sandy) and Nashua (sandy clay loam) subsurface soils, which also had the least organic matter contents. The mobility relationship of atrazine, Deethylatrazine, and deisopropylatrazine in this study (Deethylatrazine ≥ atrazine ≥ deisopropylatrazine) is consistent with groundwater monitoring reports. Similar mobilities of atrazine, deisopropylatrazine, and didealkylatrazine in some soils of this study suggest that didealkylatrazine is mobile enough to reach groundwater and therefore should be looked for in routine monitoring.
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use of undisturbed soil columns under controlled conditions to study the fate of 14c Deethylatrazine
Journal of Agricultural and Food Chemistry, 1996Co-Authors: Ellen L Kruger, Pamela J Rice, Jennifer C Anhalt, Todd A Anderson, Joel R CoatsAbstract:The fate of [14C]Deethylatrazine [2-chloro-4-amino-6-(isopropylamino)-s-triazine] was studied under controlled conditions by using undisturbed soil columns in the laboratory. In a 13-week leaching study, the percentage of [14C]Deethylatrazine recovered was greatest in the first leaching event (1.3% of the applied 14C), suggesting that preferential flow occurred. The total concentration of Deethylatrazine leached from soil columns over the 13-week period was 4.9 μg/L (3.6% of the applied 14C). Unidentified polar degradates made up 3.8% of the applied radioactivity recovered in the leachate, and didealkylatrazine [2-chloro-4,6-(diamino)-s-triazine] and deethylhydroxyatrazine [2-hydroxy-4-amino-6-(isopropylamino)-s-triazine] occurred in trace quantities. Sixty-seven percent of the applied 14C remained in the top 10 cm of soil columns, with 48% as bound residues, 12% as unidentified polar degradates, 5.5% as Deethylatrazine, 0.2% as didealkylatrazine, and less than 0.1% as deethylhydroxyatrazine. Keywords: At...
