Dissipation Kinetics and the Pre-Harvest Residue Limits of Acetamiprid and Chlorantraniliprole in Kimchi Cabbage Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

Abstract

The dissipation behaviors of acetamiprid and chlorantraniliprole in kimchi cabbages were studied under open-field conditions. A simple and rapid analytical method was developed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The multiple reaction monitoring (MRM) conditions of two pesticides were optimized to quantify and identify the pesticide residues. Sample preparation was performed by the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method. Average recovery rates at the different spiked levels (0.05 and 0.25 mg/kg) were in the range of 103.6–113.9% (acetamiprid) and 80.8–91.2% (chlorantraniliprole), and the relative standard deviations were ≤4.3% for all. The dissipation kinetics were assessed using first-order equations after spraying acetamiprid and chlorantraniliprole individually on kimchi cabbages. The biological half-lives in field 1 and 2 were 5.2 and 6.3 days (acetamiprid) and 10.0 and 15.2 days (chlorantraniliprole), respectively. Based on the dissipation equations, the pre-harvest residue limits (PHRLs) corresponding to each day before harvest were suggested as the guidelines to meet the MRL on harvest day. It was also predicted that the terminal residues observed after multiple sprayings (three and seven days) would be below the MRL when harvested, in compliance with the established pre-harvest intervals.

Monarch Butterfly (Danaus plexippus) Life‐Stage Risks from Foliar and Seed‐Treatment Insecticides

“…Thiamethoxam was expected to cause the least mortality via both foliar application methods (100 to 17% at 0 and 60 m downwind). A more realistic estimate of mortality could take into account the insecticide half‐lives (chlorpyrifos, 4–6 d [Galietta et al 2011; Szpyrka et al 2017]; chlorantraniliprole, 3–17 d [Lee et al 2019; Szpyrka et al 2017]; imidacloprid, 2–5 d [Mukherjee and Gopal 2000; Banerjee et al 2012]; thiamethoxam, 4–6 d [Rahman et al 2015]; and clothianidin, 4 d [Chowdhury et al 2012]), which are shorter than the length of the entire larval stage (12–13 d at 27 and 25 °C, respectively [Rawlins and Lederhouse 1981; Zalucki 1982]). Assuming an insecticide half‐life of 4 d, estimated exposure would drop approximately 2.4‐fold for neonates that hatch on the day of application and 4.8‐fold for neonates that hatch 4 d later.…”

“…Krishnan et al (2020) estimated field-scale acute topical and dietary risks to different larval instars following single foliar applications of beta-cyfluthrin, chlorantraniliprole, chlorpyrifos, imidacloprid, and thiamethoxam (acute foliar risks for clothianidin presented in Supplemental Data, Table S1). The half-lives of these insecticides on growing plants range from 1 to 17 d (Mukherjee et al 2000;Galietta et al 2011;Banerjee et al 2012;Chowdhury et al 2012;Szpyrka et al 2017;Lee et al 2019). Consequently, larvae that survive the initial exposure from a spray drift event, as well as larvae that hatch from eggs laid after a spray drift event, could be exposed to insecticide residues through a significant portion of their life stage, which ranges from 12 to 13 d (Rawlins and Lederhouse 1981;Zalucki 1982).…”

Residue kinetics of neonicotinoids and abamectin in pistachio nuts under field conditions: model selection, effects of multiple sprayings, and risk assessment

“…Also, farmers usually apply frequent sprayings weeks before harvest depending on pest abundance, and it is not clear how these multiple sprayings affect the final pesticide residues at harvest time. Parameters obtained from statistical models would help predict pesticide accumulation/dissipation in pistachio nuts and their residues at harvest time under different multiplespraying scenarios (Torabi et al 2017;Hwang et al 2018;Lee et al 2019;Liu et al 2021). The model predictions are used subsequently to conduct pesticide risk assessments for humans via the consuming pistachio nuts.…”

“…These distribution processes result in decreased pesticide levels in sap water compared to the outside surface concentrations, which will keep the driving force for passive uptake of the chemicals until reaching the partition limit (e.g., an equilibrium) (Liu et al 2021). Also, several exponential decay models, including the simple first-order kinetic (SFOK), zero-order (ZO), second-order (SO), and first-order double-exponential decay (FODED), have been utilized to predict the dissipation trends of agrochemicals in crops (Utture et al 2012;Torabi and Talebi 2013;Rahimi et al 2015;Ramezani and Shahriari 2015;Chen et al 2016;Alister et al 2017;Torabi et al 2017;Lee et al 2019). SFOK, ZO, and SO are log-linear models which consider pesticide dissipation a mono-phasic process with a single rate constant (see Eqs.…”

“…The initial concentration of a pesticide readily available to the degrading enzymes in the solution phase dissipates quickly. The remaining part, which may be absorbed into the plant tissue particles, comes to a dynamic equilibrium and degrades slowly (Chen et al 2016;Alister et al 2017;Lee et al 2019).…”