Evaluation of Different Decontamination Studies of Imidacloprid 17.8 SL on Okra

Abstract

Okra is the major crop grown all over India. India is the largest producer of okra in the world with the largest productivity. The crop is susceptible to a wide range of sucking pests hence there is an indiscriminate usage of pesticide on okra. A detailed survey was conducted to analyze the pest and pesticide status of okra growing farmers of Tirunelveli and Thoothukudi districts. The survey reported that the higher number of farmers was found to use imidacloprid 17.8 SL for the management of sucking pests on okra. Different decontamination studies were carried out to evaluate a suitable decontamination method for the imidacloprid residues on okra. The different treatments employed were washing in tap water for 2 min. (T1), washing in tap water for 2 mins. + Dipping in 2 per cent salt solution for 30 sec. (T2), washing in tap water for 2 mins. + Dipping in 2 per cent tamarind solution for 30 sec. (T3), washing in tap water for 2 mins. + Dipping in 2 per cent salt solution for 30 sec. + cooking for 10 mins. (T4), washing in tap water for 2 mins. + Dipping in 2 per cent tamarind solution for 30 sec. + cooking in 10 mins. (T5), washing in tap water for 2 mins. + cooking for 10 mins. (T6) and untreated sample (T7). The extraction and clean up were done using QuEChERS method. The analysis of samples was done using UHPLC (Ultra High Performance Liquid Chromatography) with photo diode array detector. From the experiment conducted, the results indicated that the mean initial deposit of imidacloprid residue detected in untreated sample was detected to be 0.29 µg g-1. The mean residue level decreased to 0.16, 0.12, 0.13, 0.05, 0.05 and 0.08 µg g-1 after different processes like washing in tap water, dipping in 2 per cent salt solution, dipping in 2 per cent tamarind solution, dipping in 2 per cent salt solution followed by cooking, dipping in 2 per cent tamarind solution followed by cooking and cooking alone. The treatments T4 and T5 showed the highest decontamination percentage of 84.59 and 83.91 mean per cent, respectively.