Dissipation kinetics, decontamination and dietary risk assessment of imidacloprid residue in bitter gourd and soil

Abstract

Imidacloprid is a broad-spectrum neonicotinoid class insecticide with systemic action, widely used on vegetables in India for the management of sucking insect pests. The overall pesticide usage profile in gourds growing districts of Tamil Nadu showed that imidacloprid as the most commonly used insecticide. The present study aimed to develop and validate an analytical approach for detecting imidacloprid and 6-chloronicotinic acid residues in bitter gourd fruit, juice and soil using LC-EI-MS (liquid chromatography coupled with electron ionization mass spectrometry) was undertaken. The persistence pattern, effect of household processing and risk assessment of imidacloprid on bitter gourd was studied by conducting field trials at single and double doses of 20 and 40 g a.i ha-1. Calibration curves showed a good linear relationship (r2>0.99) with the concentrations (0.0025–0.5 µg mL-1) of imidacloprid and 6-chloronicotinic acid. The limit of detection and quantification of the method were 0.008 and 0.025 mg kg-1, respectively. Accuracy of imidacloprid and 6-chloronicotinic acid residue recovery was in the range of 88–101 per cent with RSD of less than six per cent in all the matrices of bitter gourd. Initial deposits of imidacloprid at 20 and 40 g a.i ha-1 were 0.68 and 1.25 mg kg-1 and the residues persisted up to 10 and 15 days with their respective half-lives of 2.51 and 3.13 days. Simple decontamination techniques showed 33 to 80 per cent reduction of residues in samples collected up to 10 days after treatment. The estimated RQ was less than one indicating the level of risk to the consumer is negligible.

Unraveling the Potential of Household Electrolytes on Extricating Imidacloprid Residues from Tomatoes: Toxicity Assessment

“…But however these methods may results in loss of vitamins etc. Suganthi et al [10] stated that the decontamination techniques reduced imidacloprid residues in bitter gourd by 33-80% in 10 days and mentioned minimal risk to consumers, with RQ < 1 after 10 days of imidaclorpid application Naik et al [11] studied the decontamination of imidacloprid from brinjal and okra involving boiling found that the removal up to 96.43% and 73.66% residues from brinjal and okra, respectively. Despite the fact that heat methods are used for decontaminating pesticides in many cases, there is a potential that some vegetables, notably tomato fruit, will lose quality.…”