| 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. |