Magnetic solid‐phase extraction or dispersive liquid–liquid microextraction for pyrethroid determination in environmental samples

Abstract

The determination of 15 pyrethroids in soil and water samples was carried out by gas chromatography with mass spectrometry. Compounds were extracted from the soil samples (4 g) using solid-liquid extraction and then salting-out assisted liquid-liquid extraction. The acetonitrile phase obtained (0.8 mL) was used as a dispersant solvent, to which 75 μL of chloroform was added as an extractant solvent, submitting the mixture to dispersive liquid-liquid microextraction. For the analysis of water samples (40 mL), magnetic solid-phase extraction was performed using nanocomposites of magnetic nanoparticles and multiwalled carbon nanotubes as sorbent material (10 mg). The mixture was shaken for 45 min at room temperature before separation with a magnet and desorption with 3 mL of acetone using ultrasounds for 5 min. The solvent was evaporated and reconstituted with 100 μL acetonitrile before injection. Matrix-matched calibration is recommended for quantification of soil samples, while water samples can be quantified by standards calibration. The limits of detection were in the range of 0.03-0.5 ng/g (soil) and 0.09-0.24 ng/mL (water), depending on the analyte. The analyzed environmental samples did not contain the studied pyrethroids, at least above the corresponding limits of detection.

Poly (Ionic Liquids) Functionalized Magnetic Nanoparticles as Efficient Adsorbent for Determination of Pyrethroids from Environmental Water Samples by GC‐MS

“…The extraction efficiency remained relatively steady with the sample pH increasing to 11. Based on published literatures, the sample pH was set at 7 in further experiment.…”

Dispersive solid‐phase extraction combined with dispersive liquid‐liquid microextraction for simultaneous determination of seven succinate dehydrogenase inhibitor fungicides in watermelon by ultra high performance liquid chromatography with tandem mass spectrometry

“…Sample pretreatment processes take an important role in the analytical procedure. The classic sample preparation methods (i.e., LLE and SPE) have been widely developed for extraction and cleanup in the residue analysis . However, the classic sample preparation method consumes a large amount of toxic and expensive organic solvents (i.e., LLE), wastes time and has an insufficient sensitivity .…”

Magnetic solid‐phase extraction of pyrethroid pesticides in environmental water samples with CoFe2O4‐embedded porous graphitic carbon nanocomposites

“…However, the concentrations of analytes are very low and the sensitivity of direct detection is often inadequate in complex matrix. Some sample pretreatment technologies including SPE and liquid-liquid microextraction have been combined with the modern instrument to obtain better analysis results [2,6,[13][14][15][16][17][18]. Different pretreatment technologies have greatly improved the analytical ability.…”