Development of in-situ synthesis of lighter than water deep eutectic solvents under ultrasonic energy in a narrow tube and application in liquid–phase microextraction

Abstract

ABSTRACT Evaluation of sonication energy effect on in-situ synthesis of deep eutectic solvent-based liquid phase microextraction process was performed in fresh fruit samples for extraction of five neonicotinoids insecticide including clothianidin, imidacloprid, nitenpyram, acetamiprid, and thiacloprid. A suitable amount of choline chloride was dissolved in sample solution and it was poured into a glass narrow-bore tube. Then, a sodium chloride tablet was taken and a few microlitres of hexanoic acid were penetrated into the tablet and it was released into the tube. The narrow–bore tube was located into an ultrasonic bath at controlled frequency and power. The sodium chloride tablet started to dissolve and hexanoic acid was released into the solution and hydrogen bonding was correlated between the ChCl and hexanoic acid. The formed deep eutectic solvent went up through the sample solution and analytes were extracted into the ChCl: hexanoic acid DES. Validation parameters were calculated and low limits of detection (0.04–0.31 ng mL–1) and quantification (0.13–1.03 ng mL–1), high enrichment factors (1280–1780) and extraction recoveries (64–89%), and acceptable precision (RSD ≤7.2%) were obtained. Lastly, the procedure was done on some fresh fruit samples imidacloprid and acetamiprid were detected on some samples.