Evaluating the effectiveness of different household washing techniques for removal of insecticides from spinach and chickpea leaves by micellar liquid chromatography

Abstract

In the past few decades, the employment of green analytical approaches in chromatographic method development has attracted the analytical separation community. The greenness of the developed method depends upon the toxicity of solvents and the amount of generated post-analysis waste generated. In this concern, micellar liquid chromatography (MLC) is a simple and rapid technique that generates very low toxic waste compared to traditional chromatographic pesticide detection methods. Here, MLC method has been validated and applied for the determination of monocrotofos (MCF), imidacloprid (ICP), dimethoate (DM) and profenofos (PFF) in spinach and chickpea leaves. The optimized mobile phase was 0.065 M SDS-2 % 1-propanol, 0.01 M NaH2PO4 buffered to pH 7. A C18 column was used for separation with a flow rate of 1 mL/min. The developed method has been validated following the guidelines of SANTE/11,312/2021 and ICH guidelines for; limit of quantification (0.05–0.20 mg/kg), linearity (r2> 0.997–0.999), precision (<6.3 %), accuracy (96.3 %–99.8 %) and robustness (<6) in real samples. ICP and MCF, apart from DM and PFF, were detected in the present work. After detecting insecticides in spinach and chickpea leaves both were washed with different household chemicals i.e. normal, lukewarm, common salt, lemon juice water and commercial ozonizer. Based on five washing techniques with insecticide concentration time intervals reduction rates were calculated for each washing treatment. The results show that lemon juice, common salt water, and ozonizer can be used as washing techniques for the reduction of superficial and systematic residues of ICP and MCF. Common salt and lemon juice water were better for washing over vinegar and potassium permanganate (KMnO4) as they enhance the colour of the green leafy vegetables and are available in every Indian kitchen. They can be easily used by lower socioeconomic classes who cannot afford KMnO4 and vinegar.