Mahboube Shirani

In this research study, the rapid and simple method of dispersive liquid–liquid microextraction method based on solidification of floating organic drop (DLLME-SFO) was used for simultaneous separation/preconcentration of deltametrin and cypermethrin from agricultural soil and water samples. The analytes were determined by gas chromatography-mass spectrometry. The influential parameters of DLLMESFO including type and volume of extraction solvent type, type and volume of dispersive solvent, sample volume were optimized. A mixture of 1 mL methanol as dispersive solvent, 10 μL 2-dodecanol was rapidly injected into the 10 mL aqueous solution. A cloudy solution was formed. The solution was centrifuged for 3 min at 5500 rpm. The test tube was then cooled in an ice bath. After 5 min the 2-dodecanol solidified and was then transferred to a conical vial; it melted quickly at room temperature and 1 μL of it was injected into a gas chromatograph-mass spectrometry for analysis. The limits of detection (LOD) of 0.005 and 0.008 μg L−1 were obtained for deltametrin and cypermethrin respectively. The linear range of 0.01-500 μg L−1 with a coefficient (r2) of 0.999 was obtained for both analytes. The proposed method was successfully applied for determination of trace amount of deltametrin and cypermethrin in agricultural soil and water samples.