High Density Supercritical Carbon Dioxide for the Extraction of Pesticide Residues in Onion with Multivariate Response Surface Methodology.

Teshome Tolcha,Tura Gemechu,Charlotta Turner,Said Al-Hamimi,Negussie Megersa

doi:10.3390/molecules25041012

Abstract

The excessive use of pesticides is a serious health problem due to their toxicity and bioaccumulation through the food chain. Due to the complexity of foods, the analysis of pesticides is challenging often giving large matrix effects and co-extracted compounds. To overcome this problem, a selective and “green” supercritical fluid extraction method was developed, using neat carbon dioxide as a solvent at pressures of up to 800 bars. A Box–Behnken response surface experimental design was used, with the independent variables of density (0.70−1.0 g mL−1), temperature (40−70 °C), and volume (10−40 mL) of solvent, and the dependent variable of extracted amount of pesticides. The optimum extraction condition was found at the use of 29 mL of supercritical CO2 at 0.90 g mL−1 and 53 °C (corresponding to 372 bars of pressure). It was observed that increasing the density of CO2 significantly increased the extraction recovery of endrin and 2,4′-dichlorodiphenyldichloroethane. Matrix-matched calibration curves showed satisfactory linearity (R2 ≥ 0.994), and LODs ranged from 0.2 to 2.0 ng g−1. Precision was lower than 11% and recoveries between 80%–103%. Thus, the developed method could efficiently be used for trace analysis of pesticides in complex food matrices without the use of organic solvents.

Highlights

The use of chemical pesticides in modern agriculture to ensure food security has increased over the past decades [1,2]
What is unique is that ultrahigh pressure supercritical fluid extraction (SFE) (UHPSFE) is used for the extraction of pesticides, atrazine, 2,4 ́-DDD, 4,4 ́-DDT and endrin, from a food sample, in this case onion
We have demonstrated that oleifera and Moringa peregrina seed lipids could be efficiently extracted using UHPSFE, giving a clean

Summary

Introduction

The use of chemical pesticides in modern agriculture to ensure food security has increased over the past decades [1,2]. The extensive application of these compounds and their degradation products contaminate the environment and agricultural products [5,6]. Water-soluble compounds are transported to surrounding water and eventually enter the food chain [7,8]. Lipophilic compounds like organochlorine can concentrate in fatty tissues and bioaccumulate in the food chain [2]. Applications of organochlorine and s-triazine pesticides have been banned in developed countries, developing countries like Ethiopia are still using them for agricultural and medicinal purposes. Studies carried out in various agro-industries in Ethiopia showed the presence of contaminant pesticide residues in different samples collected from various localities of Ethiopia [6]

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