Ultrasound Assisted-Homogeneous Liquid-Liquid Phase Microextraction based on Deep Eutectic Solvents and Ethyl Acetate for Preconcentration of Selected Organochlorine Pesticides in Water Samples

Abstract

A novel and greener methodology for the simultaneous preconcentration of
organochlorine pesticides in water samples based on ultrasound assistedhomogeneous liquid-liquid phase microextraction (UA-HLLME) has been developed.
Gas chromatography-time of flight mass spectrometry was used for quantification of
OCPS in water samples. In this method, choline-chloride-ethylene glycol deep eutectic
solvent and ethyl acetate were used as the disperser solvent and extraction solvent,
respectively. Univariate and multivariate approaches were used for optimization of the
influential parameters that affect the extraction efficiency of the UA-HLLME method.
Under the optimum conditions, enrichment factors ranging from 152 to 403 with
acceptable recoveries of 85-100% were obtained. The dynamic linear ranges were
obtained in the concentration range 0.015–1000 μg L−1 with correlation coefficients
ranging 0.9952–0.9995. The limits of detection and quantification of the developed UAHLLME method were in the range 1.9-8.6 ng L−1 and 5.9-26 ng L−1, respectively. The
intra-day and inter-day precision expressed in terms of relative standard deviation
(%RSD) ranged from 2.1-4.5% and 3.9-7.3%, respectively. The developed method was
successfully applied for the preconcentration and determination of the selected OCPs
from 3 different river water samples. The developed procedure displayed simplicity,
environmental friendliness, relatively high extraction efficiency, short analysis time and
relatively low detection limits.