| In the present study, a sample pretreatment based on the combination of vortex assisted liquid–liquid extraction and dispersive
liquid–liquid microextraction has been proposed for the isolation
and preconcentration of three acidic herbicides including fenoxaprop, fluazifop, and haloxyfop from edible oil samples. For this
purpose, firstly, the analytes were extracted into sodium hydroxide
solution (by deprotonating the analytes) which was used as
a dispersive solvent in the following microextraction procedure.
The obtained aqueous phase was mixed with acetic acid as a pH
adjustment agent and co–disperser solvent. After the addition of
dichloromethane (extraction solvent) to the above solution, it was
quickly dispersed into deionised water. The validation parameters
indicated that the limits of detection and quantification of the
proposed method were in the ranges of 0.3–1.8 and
1.0–6.0 ng mL–1
, respectively. Relative standard deviations of the
method were obtained in the range of 4.8–6.2% and 5.2–9.1% for
intra – (n = 6) and inter–day (n = 5) precisions, respectively. High
extraction recoveries and enrichment factors ranged from 74 to
91%, and 185 to 227 were the other advantages of the method.
These merits showed that the proposed method is efficient and
sensitive for the determination of the studied analytes in the edible
oil samples. |