Vol. 8, Issue 6 (2019)

Author(s):
M Bhavadharani, P Janaki, R Sheeba Joyce Roseleen, K Arulmozhiselvan and J Ejilane

Abstract:
A perceptible increase of pesticides usage in agriculture needs on-site monitoring of their residues to increase the food safety and avoid health issues. Here, the present investigation was carried out to evaluate a rapid enzyme based test kit to detect the presence of cholinesterase-inhibiting pesticides in vegetables. The inhibition of acetylcholinesterase enzyme (AChE) by OP and pesticides using specific substrate, acetylthiocholine and suitable chromogenic reagent was evaluated and observed for the colour development. Initially it was evaluated with technical standards and fortified vegetable samples to find out the lowest limit of colour development for each pesticide and then extended to the fortified and unknown vegetable samples. Increase in pesticide concentration decreased the yellow colour intensity and the developed colour was also analyzed in spectrophotometer for validating the test technique and calculating the AChE inhibition percent. Under optimized condition, the detection limit of 2 mg/L for chloripyriphos, profenofos and dimethoate and 1 mg/L for triazophos, quinalphos, ethion and dicofol was achieved. Pesticide residues from fortified and unknown vegetables were extracted by QuEChERS method and assayed by the developed rapid enzyme test and spectrophotometer. The total amount of time required for detection of pesticide residue using rapid AChE based test is a minute. The main advantage of the developed rapid test kit is minimum reagent requirement, low-cost and easy to handle. Even non-professional can screen pesticide residue using the developed rapid test kit.