Dissipation studies of fentrazamide (YRC-2388) in soil under anaerobic condition

Abstract

Dissipation of fentrazamide in soil and water under flooded (anaerobic) conditions was studied. Fentrazamide was applied to soil at 100 g ha(-1). Soil was extracted with 0.1 N HCl : acetone (1 : 1 v/v) followed by partition and cleanup with silica SPE. Separation was achieved in an ODS-II column with a mobile phase of acetonitrile : water (70 : 30 v/v) and detection at 214 nm. Recovery of fentrazamide varied from 75.2-90.4% and 89.9-97.8% in soil and water, respectively. Fentrazamide dissipated rapidly and fentrazamide residues were not detected after 100 and 35 days of application in soil and water, respectively. Half life in soil and water was 9.06 and 3.66 days, respectively. Dissipation followed monophasic first order kinetics pattern. No fentrazamide was detected in soil, rice grain and rice straw at harvest of crop. Calibration curves for quantification were linear and relative standard deviation (RSD) was 1.78%. LOD for instrument was 0.002 μg mL(-1) and LOQ for methods were 0.005 μg g(-1) for soil and water.

Dissipation kinetics and leaching of cyazofamid fungicide in texturally different agricultural soils

“…High temperature and humidity favor rapid degradation of pesticide in soil as these factors favor high microbial population and activity. In general, microbial activity increases in warm, moist and well-aerated soils, and rate of degradation decreases when there is low (temperature, 1989;Tiryaki and Temur 2010;Tandon et al 2012a;b) Dissipation was faster in silty clay loam compared to sandy loam, which would be attributed to the fact that silty clay loam soil is rich in organic carbon content; hence, more microbial activity would be in soil and microbes play significant role in degradation of fungicide. Beside this, it has higher percentage of clay; the fungicide is more adsorbed on its active sites and it will react with the molecule and would degrade (hydrolysis) or form bound residues.…”

Anaerobic Degradation of [14C]Methiozolin under Aquatic Sediment Conditions

“…Although methiozolin is already widely used, there is limited research on the mechanisms of degradation and dissipation in low-oxygen and sediment-water environments. Anaerobic research can reveal the mechanisms of xenobiotic degradation in the environment, but the effects of anaerobic processes on herbicide and insecticide persistence have not been thoroughly investigated. − When pesticides are sprayed, there is a high chance that they will partition into anoxic environments, such as flooded soils, landfills, and sludge or sediments through drainage, spray drift, runoff, and waste disposal. − Leaching or runoff following heavy rains could cause pesticides to enter shallow or deep surface waters associated with sediments, where anaerobic processes can occur. , When measuring the intensity of anaerobic conditions, most studies have used the redox potential. The International Test Guidelines of the Organization for Economic Co-Operation and Development (OECD No.…”