| In this study, a new two–step extraction procedure based on the combination of a modified quick, easy, cheap, effective, rugged, and safe extraction method with a deep
eutectic solvent based microwave-assisted dispersive liquid–liquid microextraction
has been developed for the extraction of multiclass pesticides in tomato samples before
their analysis by gas chromatography with flame ionization detection. In this method,
initially, an aliquot of tomato is crushed and diluted with deionized water. The mixture
is then passed through a filter paper and its residue and aqueous phase are separated.
Afterwards, acetonitrile as an extraction/disperser solvent is passed through the filter
paper containing the refuse. The analytes remained in the refuse are extracted into the
acetonitrile and then the obtained extract is mixed with a deep eutectic solvent. The
obtained mixture is injected into the tomato juice and placed in a microwave oven for
15 s. Consequently, a cloudy state is formed and the extractant containing the analytes
are sedimented at the bottom of the tube after centrifugation. Finally, 1 μL of the sedimented phase is removed and injected into the separation system. Under the optimum
conditions, limits of detection and quantification were in the ranges of 0.42–0.74 and
1.4–2.5 ng/g, respectively. |