Abstracts
Diclosulam
CAS No. 145701-21-9
For more abstracts search PubMed or Toxnet
 
 

Return to
Index Page
Adverse Effects

ACTIVITY: Herbicide (Triazolopyrimidine)

CAS Name: N-(2,6-dichlorophenyl)-5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonamide

Structure:



Journal of Chromatography A - Volume 1070, Issues 1-2 , 8 April 2005, Pages 171-177

Determination of herbicides in mineral and stagnant waters at ng/L levels using capillary electrophoresis and UV detection combined with solid-phase extraction and sample stacking

Javier Hernández-Borges (a), Francisco J. García-Montelongo (a), Alejandro Cifuentes (b) and Miguel Ángel Rodríguez-Delgado (a)

(a) Department of Analytical Chemistry, Nutrition and Food Science, University of La Laguna, Avda. Astrofísico Fco. Sánchez s/n, 38071 La Laguna, Santa Cruz de Tenerife, Spain
(b) Department of Food Analysis, Institute of Industrial Fermentations (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain

In this work, the combined use of solid-phase extraction (SPE) and on-line preconcentration strategies as normal stacking mode (NSM) and stacking with matrix removal (SWMR) for the ultrasensitive and simultaneous capillary electrophoresis-ultraviolet analysis (CE-UV) of five triazolopyrimidine sulfonanilide pesticides (i.e., diclosulam, cloransulam-methyl, flumetsulam, metosulam and florasulam) in different types of water is investigated. An adequate separation electrolyte for the separation and stacking of these pesticides was obtained, considering also its compatibility with MS detection, which consisted of 24 mM formic acid and 16 mM ammonium carbonate at pH 6.4. It was observed that the use of this running buffer together with the SWMR preconcentration method provided the best results in terms of sensitivity (between 6.54 and 11.9 ?g/L) and peak efficiency (up to 550 000 theoretical plates per meter, NTP/m). When this on-line preconcentration procedure was combined with an off-line sample preconcentration step as SPE using C18 cartridges, the selected herbicides could be detected in the ng/L range. The optimized SPE-SWMR-CE-UV method was applied to the determination of the selected group of pesticides in spiked and non-spiked mineral and stagnant waters. Recoveries ranged between 55 and 110% and limits of detection between 131 and 342 ng/L. This work shows the great possibilities of the combined use of SPE-SWMR-CE-UV to overcome the sensitivity problems usually linked to CE analysis.

• Note from FAN: Four of the five triazolopyrimidine sulfonanilide pesticides cited are fluorinated:
diclosulam, cloransulam-methyl, flumetsulam, and florasulam


Crop Protection - Volume 23, Issue 11 , November 2004, Pages 1145-1149

Short communication

Using diclosulam in a weed control program for peanut in South Texas

W. James Grichar (a), Brent A. Besler (a), Kevin D. Brewer (a) and Vernon B. Langston (b)

(a) Texas Agricultural Experiment Station, 3507 Hwy 59E, Beeville, TX 78102, USA
(b) Dow AgroSciences, The Woodlands, TX 77382, USA

Field studies were conducted during the 1997 and 1998 growing seasons to evaluate diclosulam alone and in combination with ethalfluralin for Eclipta prostrata, Ipomoea lacunosa, Panicum texanum, and Cyperus esculentus control. Diclosulam alone or in combination with ethalfluralin-applied preplant incorporated (PPI), preemergence (PRE), or postemergence (POST) at 0.009 to 0.024 kg ai/ha provided at least 93% season-long Eclipta control. Ethalfluralin, in combination with diclosulam-applied PPI at 0.016 or 0.024 kg ai/ha controlled C. esculentus at least 82% season-long. Ethalfluralin followed by diclosulam-applied POST at 0.016 or 0.024 kg/ha controlled at least 90% Ipomoea season long, while ethalfluralin followed by diclosulam-applied PPI or PRE at 0.024 kg/ha controlled 81%. Ethalfluralin in combination with diclosulam at 0.016 kg/ha or ethalfluralin followed by diclosulam at 0.016 or 0.024 kg/ha applied POST controlled greater than 80% P. texanum throughout the growing season. Diclosulam offers more effective Eclipta control than the commerical standards now being used.

• Note from FAN: Ethalfluralin is a fluorinated pesticide.


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11453764&dopt=Abstract

J Agric Food Chem. 2001 Jul;49(7):3284-90.

Terrestrial field dissipation of diclosulam at four sites in the United States.

Zabik JM, van Wesenbeeck IJ, Peacock AL, Kennard LM, Roberts DW.

Dow Agrosciences LLC, Building 306/A2, 9330 Zionsville Road, Indianapolis, Indiana 46268, USA. jmzabik@dowagro.com

The soil dissipation of diclosulam was studied using 14C-labeled and nonradiolabeled material in Mississippi, North Carolina, Georgia, and Illinois between 1994 and 1997. The test substance was preemergence broadcast applied at target rates of 35 and 37 g ai x ha(-1) for the 14C-labeled and the nonradiolabeled studies, respectively. The degradation of diclosulam was rapid with half-lives ranging from 13 to 43 days at the four sites. Rapid degradation rates and the increasing sorption to soil over time resulted in low persistence and mobility of this compound. Metabolite formation and dissipation in the field reflected observations of photolysis, hydrolysis, and aerobic soil metabolism studies in the laboratory. The rapid field dissipation rates, metabolite formation patterns, and sorption characteristics obtained in these field studies were consistent with the laboratory data generated for diclosulam, and reflect the multiple concurrent degradation mechanisms occurring in the field.

PMID: 11453764 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11285917&dopt=Abstract

J Environ Qual. 2001 Mar-Apr;30(2):553-60.

Measurement and modeling of diclosulam runoff under the influence of simulated severe rainfall.

van Wesenbeeck IJ, Peacock AL, Havens PL.

Dow AgroSciences, Bldg. 306/A2, 9330 Zionsville Road, Indianapolis, IN 46268, USA. iwesenbeeck@dowagro.com

A runoff study was conducted near Tifton, GA to measure the losses of water, sediment, and diclosulam (N-(2,6-dichlorophenyl)-5-ethoxy-7-fluoro-[1,2,4]triazolo-[1,5c]-pyrimidine- 2-sulfonamide), a new broadleaf herbicide, under a 50-mm-in-3-h simulated rainfall event on three separate 0.05-ha plots. Results of a runoff study were used to validate the Pesticide Root Zone Model (PRZM, v. 3.12) using field-measured soil, chemical, and weather inputs. The model-predicted edge-of-field diclosulam loading was within 1% of the average observed diclosulam runoff from the field study; however, partitioning between phases was not as well predicted. The model was subsequently used with worst-case agricultural practice inputs and a 41-yr weather record from Dublin, GA to simulate edge-of-field runoff losses for the two most prevalent soils (Tifton and Bibb) in the southeastern U.S. peanut (Arachis hypogaea L.) market for 328 simulation years, and showed that the 90th percentile runoff amounts, expressed as percent of applied diclosulam, were 1.8, 0.6, and 5.2% for the runoff study plots and Tifton and Bibb soils, respectively. The runoff study and modeling indicated that more than 97% of the total diclosulam runoff was transported off the field by water, with < 3% associated with the sediment. Diclosulam losses due to runoff can be further reduced by lower application rates, tillage and crop residue management practices that reduce edge-of-field runoff, and conservation practices such as vegetated filter strips.

PMID: 11285917 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10995360&dopt=Abstract

J Agric Food Chem. 2000 Sep;48(9):4335-40.

Aerobic metabolism of diclosulam on U.S. and South American soils.

Yoder RN, Huskin MA, Kennard LM, Zabik JM.

Global Environmental Chemistry Laboratory, Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, Indiana 46268, USA. rnyoder@dowagro.com

Degradation of the sulfonanilide herbicide diclosulam was studied on nine soils from three countries to determine the rates and products of aerobic metabolism. Diclosulam was applied to four agricultural soils from the United States, three from Argentina, and two from Brazil at a rate of 0.1 ppm, equivalent to approximately twice the maximum field application rate of 52 g of active ingredient/ha. U.S. and Brazilian soils were incubated in the dark at 25 degrees C at 75% 0.3 bar moisture; Argentinean soils were incubated in the dark at 20 degrees C and 45% moisture holding capacity. Samples were analyzed up to one year after treatment. Two-compartment DT(50) and DT(90) values averaged 28 +/- 12 and 190 +/- 91 days, respectively. Three soil metabolites reached levels of >10% of applied in at least one soil and were identified as the 5-hydroxy analogue of diclosulam (5-OH-diclosulam), aminosulfonyl triazolopyrimidine (ASTP), and the 8-chloro-5-hydroxy analogue of diclosulam (8-Cl-diclosulam). The terminal products of diclosulam soil metabolism were mineralization to CO(2) and bound soil residues. Apparent sorption coefficients (K(d)) were determined on a subset of samples by extraction with a 0. 01 M CaCl(2) solution followed by an acidified acetone extraction. Initial sorption coefficients were similar to those obtained in a batch equilibrium study and averaged 1.1 L/kg for the six soils tested. K(d) coefficients for the metabolites, when available, tended to be slightly lower than that for diclosulam. Sorptivity of diclosulam and degradates increased with time.

PMID: 10995360 [PubMed - indexed for MEDLINE]


Return to Diclosulam Index Page

 
Fluoride Action Network | Pesticide Project | 315-379-9200 | pesticides@fluoridealert.org