Sorção e hidrólise do herbicida flazasulfuron

Flazasulfuron [1-(4,6-dimethoxypyrimidin-2-yl)-3-(3-trifluoromethyl-2-pyridylsulfonyl) urea] has been used in Brazil the selective control of monocotyledonous and dicotyledonous weeds grown in the sugarcane and tomato crops. There is a lack of information in the literature about flazasulfuron behavior in soils. In this study, flazasulfuron retention was measured in batch equilibration, at 1:1 soil/solution ratio for Brazilian surface and subsurface soil samples and hydrolysis at different pH and temperature values. Sorption and desorption experiments were carried out at concentrations of 0.07 to 5.00 mgL-1 and quantification by HPLC. Hydrolysis of flazasulfuron was dependent on temperature and pH, following a first order model. The half-life of the herbicide in aqueous solution varied from 0.76 hours at 35 oC and pH 3 to 167.4 hours at 25 oC and pH 5. Sorption isotherms were nonlinear with Kf,ads values ranging from 1.19 (1/nads = 0.40) to 27.97 (1/nads = 0.90) correlated positively and significantly to organic carbon (r= 0.78), silt (r= 0.75) and CTC (r= 0.61). Flazasulfuron adsorption was lower in samples with higher pH values, indicating a greater risk of leaching under that condition.

[1]  J. Sabadie.  Alcoolyse et hydrolyse chimique acide du chlorsulfuron , 2006 .

[2]  Linda S. Lee,et al.  Factors controlling sorption of prosulfuron by variable-charge soils and model sorbents. , 2004, Journal of environmental quality.

[3]  K. Müller,et al.  Fate and behaviour of pesticides in the agroecosystem—a review with a New Zealand perspective , 2004 .

[4]  M. Duffy,et al.  Metsulfuron methyl sorption-desorption in field-moist soils. , 2003, Journal of Agricultural and Food Chemistry.

[5]  P. Rao,et al.  Significance of anion exchange in pentachlorophenol sorption by variable-charge soils. , 2003, Journal of environmental quality.

[6]  V. L. Tornisielo,et al.  Sorption of imazaquin in soils with positive balance of charges. , 2002, Chemosphere.

[7]  A. Sarmah,et al.  Hydrolysis of sulfonylurea herbicides in soils and aqueous solutions: a review. , 2002, Journal of agricultural and food chemistry.

[8]  C. Vaz,et al.  Sorption interactions between imazaquin and a humic acid extracted from a typical Brazilian oxisol. , 2002, Journal of environmental quality.

[9]  V. L. Tornisielo,et al.  Imazaquin mobility in tropical soils in relation to soil moisture and rainfall timing , 2002 .

[10]  J. Sabadie.  Nicosulfuron: alcoholysis, chemical hydrolysis, and degradation on various minerals. , 2002, Journal of agricultural and food chemistry.

[11]  L. R. F. Alleoni,et al.  Atributos de solos tropicais e a sorção de imazaquin , 2001 .

[12]  W. C. Koskinen,et al.  Sorption and leaching potential of herbicides on Brazilian soils , 2001 .

[13]  L. Ukrainczyk,et al.  Organic chemicals in the environment , 1999 .

[14]  Fred W. Roeth,et al.  Influence of surface and subsurface soil properties on atrazine sorption and degradation , 1998, Weed Science.

[15]  G. Felding.  Pesticide Adsorption as a Function of Depth below Surface , 1997 .

[16]  J. M. Reichert,et al.  Retention of imazaquin in soil , 1997 .

[17]  Javier M. Gonzalez,et al.  Adsorption and desorption of nicosulfuron in soils , 1996 .

[18]  G. Dinelli,et al.  Primisulfuron and Rimsulfuron Degradation in Aqueous Solution and Adsorption in Six Colorado Soils , 1996, Weed Science.

[19]  S. Anderson,et al.  Effect of Soil Properties and Surfactant on Primisulfuron Sorption , 1996 .

[20]  H. Ajwa,et al.  Primisulfuron sorption on minerals and soils , 1996 .

[21]  A. Smith.  A Review of Analytical Methods for Sulfonylurea Herbicides in Soil , 1995 .

[22]  N. Rashid,et al.  Irreversible Sorption of Nicosulfuron on Clay Minerals , 1995 .

[23]  P. Stork.  Field Leaching and Degradation of Soil Applied Herbicides in a Gradationally Textured Alkaline Soil: Chlorsulfuron and Triasulfuron , 1995 .

[24]  J. Schroeder.  Chlorimuron and Imazaquin Persistence in Selected Southern Soils under Controlled Conditions , 1994, Weed Science.

[25]  Allan E. Smith,et al.  Degradation of [14C]amidosulfuron in aqueous buffers and in an acidic soil , 1993 .

[26]  J. Sabadie.  Hydrolyse chimique acide du metsulfuron méthyle , 1990 .

[27]  J. Sabadie,et al.  Dégradation du metsulfuron méthyle déposé sur divers supports minéraux , 1990 .

[28]  J. Hay.  Chemistry of sulfonylurea herbicides , 1990 .

[29]  H. M. Brown,et al.  Mode of action, crop selectivity, and soil relations of the sulfonylurea herbicides† , 1990 .

[30]  D. Drennan,et al.  ADSORPTION-DESORPTION EQUILIBRIA OF 14C-FLURIDONE AT LOW SOLUTION CONCENTRATIONS AND SOIL:WATER RATIOS , 1989 .

[31]  A. Walker,et al.  Adsorption and degradation of chlorsulfuron and metsulfuron‐methyl in soils from different depths , 1989 .

[32]  S. Harper.  Sorption of Metribuzin in Surface and Subsurface Soils of the Mississippi Delta Region , 1988, Weed Science.

[33]  A. M. Blair,et al.  A review of the activity, fate and mode of action of sulfonylurea herbicides , 1988 .

[34]  P. Shea.  Chlorsulfuron Dissociation and Adsorption on Selected Adsorbents and Soils , 1986, Weed Science.

[35]  C. Foy,et al.  Phytotoxicity and Adsorption of Chlorsulfuron as Affected by Soil Properties , 1985, Weed Science.

[36]  R. Zimdahl,et al.  Chlorsulfuron Adsorption and Degradation in Soil , 1985, Weed Science.

[37]  H. Cheng,et al.  Effects of experimental variables on 2,4,5-T adsorption-desorption in soil , 1983 .

[38]  W. C. Koskinen,et al.  Characterization of Hysteresis in the Desorption of 2,4,5-T from Soils 1 , 1979 .

[39]  R. Wauchope,et al.  Fluometuron Adsorption-Desorption Equilibria in Soil , 1974, Weed Science.

[40]  P. J. Wierenga,et al.  An Evaluation of Kinetic and Equilibrium Equations for the Prediction of Pesticide Movement Through Porous Media , 1974 .

[41]  H. Pease,et al.  Determination of mobility and adsorption of agrichemicals on soils. , 1970, Journal of agricultural and food chemistry.