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Bull Environ Contam Toxicol (2012) 89:312315 DOI 10.1007/s00128-012-0697-5
Degradation of Fentrazamide Herbicide in Soil Under Aerobic Condition
Shishir Tandon Atul Pujari N. K. Sand
Received: 23 February 2012 / Accepted: 30 May 2012 / Published online: 12 June 2012 Springer Science+Business Media, LLC 2012
Abstract Dissipation of fentrazamide in soil under aerobic conditions was studied. Fentrazamide was extracted with 0.1 N HCl: acetone (1:1 v/v) followed by partition and cleanup. Separation was done on ODS-II column with mobile phase acetonitrile: water (70:30 v/v). Recovery varied from 74.51 % to 90.10 % percent in soil. Dissipation followed rst order kinetics with monophasic pattern. Half life in soil was 9.02 days. Calibration curves were linear over the range of 0.051.00 lg mL-1 and RSD was1.82 %. LOD and LOQ were 0.002 and 0.005 lg g-1 for
soil. No residues in soil and crop were observed at harvest.
Keywords Fentrazamide Kinetics Dissipation Soil
RP-HPLC
Rice (Oryza sativa L.) is the second largest produced cereal in the world. It is staple food for more than 60 % of the world and 70 % Indian population. Weeds, being a major threat compete with rice crop for resources and thus reducing the yield signicantly. In transplanted rice, weeds causes 35 %55 % reduction of grain yields while it is more severe in direct seeded rice where losses are above 65 %76 % (Shekhar et al. 2004; Singh et al. 2005). With public awareness in
environmental, human and animal health and resistance of certain weeds to old molecules of herbicide are causing great challenges to develop new safer herbicide which are used in low doses, highly effective and eco-friendly.
Fentrazamide [4-(2-chlorophenyl)-N-cyclohexyl-N-ethyl-4,5-oxo-1H-tetrazole-1-carboxamide] a novel new tetrazoli-none/amide class herbicide developed by Bayer AG and Nihon Bayer Agro-chem with a novel chemical structure (Yanagi et al. 2001; Goto et al. 2007), used in low doses (100300 g a.i. ha-1) (Ito 2008; Chhokar et al. 2006) and have excellent efcacy as pre-emergent herbicide against grasses, annual sedges and broad leaf weeds in transplanted rice (Tomlin 2002). The selective action mechanism of fentrazamide between rice and weed species has not been claried yet, but it acts by inhibiting seedling growth by inhibiting cell elongation and cell division (Goto et al. 2001; Bger 2003; Lim et al. 2007;...