Residue Dissipation Kinetics and Safety Evaluation of Insecticides on Strawberry for the Harvest Periods in Plastic-covered Greenhouse Conditions

Abstract

BACKGROUND: Dissipation patterns of insecticides (acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam) on strawberry grown in plastic-covered greenhouse were evaluated at 7 intervals including the preharvest interval after application. This study was performed to determine the residue concentrations, half-lives and dissipation rates in strawberry for the harvest periods. METHODS AND RESULTS: Acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam were applied in accordance with critical good agricultural practices for strawberry. Strawberry samples were collected at 0, 1, 2, 3, 5, 7 and 10 days after application. Quantitaion was performed by HPLC/DAD and HPLC-MSMS system with C 18 column. The limit of quantitation (LOQ) values varied between were 0.00025~0.05 mg/kg on strawberry. The recoveries of acequinocyl, clothianidin, diflubenzuron, thiacloprid and thiamethoxam at two concentrations ranged from 70.9~ 104.9% on strawberry. The half-lives of pesticide dissipation on strawberry for two fields ranged from 1.3~8.2 days. The dissipation rates were evaluated according to the statistics method with a 95% confidence. CONCLUSION: The residue levels of insecticides (acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam) on strawberry at 0-day after application were below the specified values by Korean MRL. To estimate dissipation rate constant of pesticides on crop for harvest periods, it is important to set the pre-harvest residue limit for human health and consumer protection in Korea.

Insecticides chlorantraniliprole and flubendiamide in Aster scaber: Dissipation kinetics, processing effects, and risk assessment

“…Despite the difference in initial residues, no significant difference was observed between the dissipation constants of the two fields. According to the guidelines of the Ministry of Food and Drug Safety in Korea, when the average residue at the PHI is between 20 % and 60 % of the MRL, the PHRLs are determined using the 95 % UCL of the dissipation constant, which is calculated from the average daily residue in both fields [ 26 , 38 ]. In this regard, the dissipation constants based on the residues in both fields were −0.0920 (95 % CI, −0.1049 to −0.0791) and −0.1010 (95 % CI, −0.1297 to −0.0723) for CAP and FBD, respectively.…”

“…The PHRLs of the pesticides were estimated based on the 95 % upper confidence limit (95 % UCL) of the dissipation constant (λ) and MRLs in A. scaber using the following equation [ 24 , 26 ]: where the MRL in A. scaber is 7 mg/kg for CAP and 20 mg/kg for FBD [ 27 ].…”