Dissipation kinetics and risk assessment of chlorfenapyr on tomato and cabbage

Abstract

A field experiment was conducted over two seasons to evaluate the dissipation kinetics and assess the risks of chlorfenapyr in tomato and cabbage following foliar application of chlorfenapyr 10% SC at 100 and 200 g a.i. ha. Samples of tomato, cabbage, and soil were analyzed and quantified by gas chromatography-electron capture detector (GC-ECD). The limit of detection (LOD) and limit of quantification (LOQ) of chlorfenapyr were found to be 0.01 and 0.03 mg kg, respectively, in tomato, cabbage, and soil. The dissipation of chlorfenapyr followed first-order kinetics. The compound showed less persistence in both the vegetables and soil as the calculated half-life values of chlorfenapyr ranged between 4.54 and 7.74 days considering two different doses and seasons. The residue was below detection limit in all the untreated plant and soil samples. The pre-harvest interval (PHI) of chlorfenapyr in both the vegetables was determined to be 9-14 days regardless of dose or season. The theoretical maximum residue contribution (TMRC) of chlorfenapyr was calculated for tomato and cabbage and was found to be lower than the maximum permissible intake (MPI) of the compound. Therefore, the application of chlorfenapyr at the recommended dose in tomato and cabbage for crop protection seems to be safe from both environmental contamination and consumer safety standpoints.

Persistence and Exposure Assessment of Insecticide Indoxacarb Residues in Vegetables

“…The PHI can be defined as the minimum time interval (in days) required between the final application of pesticide and the harvest to allow the pesticide residues to fall below the maximum residue limit (MRL). It was calculated by using the following equation ( 27 ).…”

“…A simple, robust, and precise analytical method is developed and validated based on standard protocols and may be followed in the future for further investigations. The experimental location is situated in West Bengal (Eastern India), which is the leading state for vegetable production ( 27 ) and contributes 15% to the total national vegetable production ( 2 ). However, information regarding the residual behavior of indoxacarb under agro-climatic conditions of West Bengal-India is not available yet.…”

Photodegradation of Flucetosulfuron, a Sulfonylurea-Based Herbicide in the Aqueous Media Is Influenced by Ultraviolet Irradiation

“…Performance of the analytical method had been evaluated based on linearity, accuracy, precision and sensitivity [ 23 ]. Flucetosulfuron standard had been injected as 0.01, 0.02, 0.03, 0.05 and 0.10 mg L −1 to work out the calibration curve.…”

Residual Behavior and Dietary Risk Assessment of Chlorfenapyr and Its Metabolites in Radish

“…As a registered pesticide directly acting on the pests of cruciferous vegetables, chlorfenapyr has a good control effect, a long-lasting period and is not easy to degrade. At present, the residue detection of chlorfenapyr in tea [ 18 ], chieh-qua [ 19 ], pumpkin and okra [ 20 ], cabbage [ 21 , 22 , 23 ], eggplant [ 24 ], sweet persimmon [ 25 ] and leek [ 26 ] has been reported. However, there has been no report on the residual digestion dynamics of chlorfenapyr in radish and its dietary risk assessment for the population.…”