| In the present study, a stir bar sorptive extraction (SBSE) method
coupled with deep eutectic solvent (DES)-based dispersive liquid–
liquid microextraction (DLLME) has been developed for the simultaneous derivatisation and extraction of some acidic pesticides before
their analysis by gas chromatography-mass spectrometry (GC-MS). In
this method, initially, the analytes are adsorbed on a coated stir bar
from an aqueous solution. Then, the stir bar is removed and a watermiscible DES is used to elute the analytes. Afterwards, butyl chloroformate (BCF) and a water-immiscible DES are added to the obtained
elute as a derivatisation agent and an extraction solvent, respectively.
In this work, the use of common toxic organic solvents is omitted, and
for the first time, DESs are used as elution (for desorption of the
analytes from stir bar), disperser and extraction solvents. Under the
optimum conditions, the introduced method indicated high enhancement factor (EnF) (1743–3654), enrichment factor (EF) (1232–1532),
and extraction recovery (ER) (74–92%), low limit of detection (LOD)
(14–29 ng L–1
) and limit of quantification (LOQ) (47–98 ng L–1
), good
linearity (r2 ≥ 0.9969) and satisfactory repeatabilities. Finally, the proposed method was applied in the analysis of the analytes in various
fruit juice samples. |