A field trial was conducted to study the dissipation kinetics of chlorantraniliprole 18.5 % SC on cowpea fruits. The fruit samples drawn periodically were analyzed by liquid chromatography and tandem mass detection (LC-MS/MS). The initial residues of chlorantraniliprole in cowpea fruits were found to be 0.55 mg kg(-1) which dissipated rapidly, with a half-life of 1.31 days and a waiting period of 0.62 days following first order kinetics. Processing of the fruits with solutions commonly used in households reduced the insecticide residues on cowpea fruits harvested 2 h after spraying by 47.19 %-91.70 % and 44.56 %-91.25 % on fruits plucked on the third day.
A single laboratory UPLC-MS/MS method was developed and validated for the estimation of fipronil and its metabolites in fresh and dry chilli pepper fruits. Dissipation of fipronil on chilli fruits was studied following the application of fipronil (Jump 80 WG) at 40 and 80 g active ingredient (a.i.) ha(-1) in the fruiting stage of the crop. The initial deposits of total fipronil on fresh chilli fruits at single and double dose application were 0.69 and 1.43 μg g(-1), respectively, and were dissipated to below quantitation level at 27 days after application. The half-life of fipronil at single and double dose in fresh chilli pepper was 4.22 and 4.32 days and the waiting period was 25.9 and 30.6 days, respectively. Processing factor due to sun drying was calculated by measuring fipronil residues in dry chilli fruits, and it ranged from 2.96 to 3.50 during 0 to 21st day after application. Among the metabolites of fipronil, fipronil desulfenyl and fipronil sulfone had maximum residues in fresh and dried chilli, respectively, followed by fipronil sulfide. Dipping in solutions of tamarind, turmeric, vinegar and slaked lime and wet scrubbing could remove more than 90% of fipronil residues in fruits.
Dissipation behaviour of the chloronicotinyl insecticide, imidacloprid (Tatamida 17.8 % SL), in fresh and cured cardamom capsules was studied following application at doses 20 and 40 g a.i. ha(-1) in a cardamom plantation of Indian Cardamom Hills (ICH), Idukki, Kerala, India. A single-laboratory ultra performance liquid chromatography mass spectrometry (UPLC-MS/MS) method was developed and validated for the estimation of imidacloprid and its six metabolites (5-hydroxy, olefin, guanidine, urea, 6-chloronicotinic acid and nitrosimine) in fresh and cured cardamom. At the lower dose, the initial deposits of total imidacloprid residues were 1.91 and 7.23 μg g(-1), respectively, in fresh and cured cardamom. At the higher dose, the initial residues were 3.94 and 14.72 μg g(-1), respectively, in fresh and cured capsules. The residues dissipated below the quantitation level of 0.01 μg g(-1) after 21 and 28 days at lower dose and after 28 days for both at higher dose. The half-lives of imidacloprid in fresh and cured cardamom were 4.02 and 3.63 days, respectively, at lower dose and 3.61 days for both at higher dose. The waiting periods of imidacloprid on fresh and cured cardamom at lower and higher doses were 21.40, 27.10, 23.85 and 30.70 days, respectively. The mean processing factor of imidacloprid was 3.96 at 20 g a.i. ha(-1). Amongst metabolites of imidacloprid, urea had maximum residues in fresh and cured cardamom followed by 5-hydroxy and guanidine. Other metabolites such as 6-chloronicotinic acid, olefin and nitrosimine were not detected either in fresh or cured cardamom.
Dissipation and decontamination of chlorantraniliprole (Coragen 18.5 SC) in brinjal and okra fruits were studied following field application at single and double doses of 30 and 60 g ai ha(-1), and the residues of the insecticide was estimated using LC-MS/MS. Initial residues of chlorantraniliprole at single and double doses on the fruits of brinjal were 0.72 and 1.48 mg kg(-1), while on okra fruits, the residues were 0.48 and 0.91 mg kg(-1), respectively. The residues reached below detectable level of 0.01 mg kg(-1) on the 10th day. Half-life of chlorantraniliprole at 30 and 60 g ai ha(-1) on brinjal was 1.58 and 1.80 days with the calculated waiting period of 0.69 and 2.38 days, whereas on okra, the values were 1.60 and 1.70 and 0 and 1.20 days, respectively. The extent of removal of chlorantraniliprole using simple decontaminating techniques at 2 h and 3 days after spraying was 40.99-91.37% and 29.85-89.12%, respectively, from brinjal fruits and 47.78-86.10% and 41.77-86.48%, respectively, from okra fruits.
A field trial was conducted to study the dissipation of neonicotinoid insecticides, imidacloprid and acetamiprid, on chilli fruits for the estimation of its half-life and waiting period. The samples of chilli fruits drawn at 0, 1, 3, 5, 7, 15, 21 days after spraying were quantified on gas liquid chromatography equipped with Ni 63 electron capture detector for acetamiprid and high performance liquid chromatography for imidacloprid. The residues of imidacloprid persisted up to seven days, whereas the acetamiprid persisted up to fifteen days of spraying. From the dissipation data, the half-life values of acetamiprid and imidacloprid were 2.27 and 2.08 days, respectively. A waiting period of 7.18 and 11.26 days were calculated for acetamiprid and imidacloprid in chilli.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.