Development of simultaneously salt and ultrasonic-assisted liquid phase microextraction for the extraction of neonicotinoid insecticides from fresh fruit juices and fruit juices

Abstract

ABSTRACT In the present study, a new microextraction method termed as simultaneously salt and ultrasonic-assisted liquid phase microextraction has been developed for the extraction and preconcentration of five neonicotinoids from fruit juices. In this method, a few microlitres of toluene (as an extraction solvent) is added onto a sodium chloride tablet and after that it is placed at the bottom of a narrow bore tube. Then, the sample solution is filled into the tube and placed into an ultrasonic bath. By this action, the tablet of sodium chloride was dissolved and the extraction solvent was released as the fine droplets. Sonication is used to accelerate dispersion of the extraction solvent and mass transfer rate of the analytes into the droplets of extraction solvent. Under optimum conditions, limits of detection and quantification were obtained in the ranges of 0.08–0.31 and 0.27–0.92 ng mL–1, respectively. The enrichment factors and extraction recoveries of the analytes ranged from 3400–4000 and 68–80%, respectively. The relative standard deviations were ≤9% for intra – (n = 6) and inter-day (n = 5) precisions. Finally, some samples including commercial fruit juice and fresh fruit juices were analysed and acetamiprid and imidacloprid were found in fresh strawberry and grape juices.