Method validation for determination of nine pesticides in okra and their mitigation using different solutions.

Anjana Srivastava,Gajan Pal Singh,Prakash Chandra Srivastava,Pankaj Bhatt

doi:10.1371/journal.pone.0260851

Anjana Srivastava, Gajan Pal Singh + Show 2 more

Open Access

https://doi.org/10.1371/journal.pone.0260851

Copy DOI

Abstract

In this paper we optimized QuEChERS method for extraction of nine pesticides viz. acephate, acetamiprid, chlorpyrifos, cypermethrin, imidacloprid, thiamethoxam, profenofos (insecticides), carbendazim and tebuconazole (fungicides) and performed their quantitative estimation in okra crop by HPLC-UV and GC-ECD. Decontamination treatments namely washing with running tap water, soaking in lukewarm water (50–60°C), soaking in solutions of 1% NaCl, 5% NaHCO3, 2% CH3COOH, 0.01% KMnO4 and three commercial formulations were also done for ten minutes every time, to calculate the extent of pesticide removal from okra. Results revealed that the proposed extraction method was efficient, inexpensive, accurate, rapid and precise and can suitably be used for the simultaneous quantitative determination of the above pesticides. The standard curve was linear over the concentration range of 0.05–5μg g-1 with R2 close to one (0.999). Soaking of okra in 2% acetic acid and then washing proved as the best decontamination treatments for all the pesticides. It showed the highest relative decontaminating capacity in comparison to the other solutions tested. Since the pesticide residues are usually present in higher amount in vegetables being consumed, it is of utmost importance to keep an eye over the use of pesticides to protect the crops.

Highlights

Vegetables are an essential component of human diet and are consumed in all forms i.e. raw or cooked and peeled or unpeeled form as they are a good source of vitamins that are essential for humans [1]
In our studies we found that solutions of 5% NaHCO3 and 0.01% KMnO4 were only slightly effective in dislodging pesticides residues from okra though it has been demonstrated that the use of sodium
As per the results obtained, recovery percentages of pesticides were between 82 to 92 percent with Relative Standard deviation (RSD) < 5%, which indicates that the QuEChERS method followed with modification and optimization of chromatographic conditions was suitable for extraction and estimation of pesticides by HPLC-UV and GC-ECD

Summary

Introduction

Vegetables are an essential component of human diet and are consumed in all forms i.e. raw or cooked and peeled or unpeeled form as they are a good source of vitamins that are essential for humans [1]. Okra [Abelmoschus esculentus (L.) Moench] commonly known as lady finger is an important vegetable crop of India, belonging toMalvaceae family. It is cultivated during spring-summer and rainy seasons but at fruiting stage, it is heavily attacked by shoot and fruit borers [2]. Pesticides having low mammalian toxicity and less risk of contamination are recommended [3].

Methods

Results

Conclusion