Dissipation Dynamics and Risk Assessment of Imidacloprid in Grape Berries Using LC- MS for Food Safety

Aim: The present study was taken up to assess the imidacloprid residue pattern in order to define strategies for improvement of quality and safety mainly healthfulness in grapes.

Place and Duration of Study: The present study was carried out in Tamil Nadu during the period 2020-2021.

Methodology: Dissipation studies were carried out in a farmer’s field at Theni, India (9o N latitude and 76o E longitude and 375m above mean sea level) with all good agricultural practices. During this study Grapes (Muscat Hamburg variety) was grown and the commercial formulation of imidacloprid 17.8% SL was applied at recommended dose (53 a.i ha-1) and double dose (106 a.i ha-1) Two sprays were given with an interval of 10 day by using a power operated sprayer as 500 L ha-1 spray fluid for dissipation study. The samples were processed by adopting modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method.

Results: The initial deposit imidacloprid in grape berries was 0.65 and 1.56 mg kg-1 at the recommended dose (53 g a.i ha-1) and double dose respectively (106 g a.i ha-1). The insecticide exhibited a slower dissipation rate and reached below its quantification level (<0.01 mg kg-1) in grape berries on 25th, 30th day at recommended and double doses respectively.

Conclusion: The toxicological dietary risk assessment data shows that risk quotient is less than one which confirms safer to consumers. Pre-harvest interval does not apply for imidacloprid at recommended dose as being grapes harvested on the day of application itself were found safe for consumption and PHI/ safe waiting period of 2 days is suggested for double dose for harvesting.