Deep eutectic solvent-based dispersive liquid–liquid microextraction for determination of organochlorine pesticides in water and apple juice samples

Abstract

In this work, we developed a deep eutectic solvent-based dispersive liquid–liquid microextraction (DES-based DLLME) method for the extraction and preconcentration of organochlorine pesticides (OCPs) from water and apple juice samples. Different DESs were synthesized by mixing menthol with carboxylic acids such as acetic, formic, and lactic acids. Among them, DES synthesized by mixing menthol with formic acid at a molar ratio of 1:1 showed the highest extraction efficiency for the target OCPs compared to other DESs. Various parameters affecting the method's extraction efficiency, including volume of DES, ionic strength, and centrifugation rate and time, were optimized. Under optimum conditions, matrix-matched calibration curves were separately constructed using water and apple juice samples. The obtained calibration curves have exhibited wide linearity ranges for both matrices. The limits of detections (LODs) and quantifications (LOQs) of the method ranged from 0.01 to 0.04, and 0.10–0.14 ng mL−1 for water and 0.05–0.09 and 0.22–0.41 ng mL−1 for apple juice samples, respectively. Similarly, the trueness of the method studied by spiking the samples at three concentration levels showed recovery values ranging from 80.1 to 112.5 % for both water and apple juice matrices. The findings demonstrated that the proposed DES-based DLLME method is rapid, simple, and environmentally benign. Thus, it could be used as an alternative method for determining OCPs in water, apple juice, and other related matrices.