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Schematic representation of the density-adjusted LPME-SDIC.

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A switchable deep eutectic solvent‐based homogeneous liquid–liquid microextraction (SDES‐HLLME) technique was developed and combined with high‐performance liquid chromatography–diode‐array detection for the determination of the chiral fungicide mefentrifluconazole. A (green) SDES was synthesized from 4‐methoxyphenyl and 3‐amino‐1‐propanol and used as an extraction solvent (thus avoiding the use of toxic extraction solvents). To improve the efficiency of the extraction process, a hydrophobic extraction solvent was subsequently generated in situ by adjusting the pH. The detection process is linear in the range of 0.01 to 1 μg ml−1. The limit of detection and limit of quantification were determined to be 0.003 and 0.01 μg ml−1, respectively. Recovery rates of 79.2% to 104.6% were acquired with relative standard deviations of 0.6% to 2.5%. The method is fast, simple, and environmentally friendly. Moreover, it was successfully used to enantioselectively determine the concentrations of mefentrifluconazole residues in water, fruit juice, and fermented liquor samples.

A simple, rapid, and environmentally friendly sample preparation method for pyrethroids determination in cereals using cyclodextrin-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplets coupled with high-performance liquid chromatography was established. The cereal samples were extracted with acetonitrile, cleaned up, and concentrated by green extractant menthol via γ-cyclodextrin assisted extraction process. The extractant menthol dispersed as fine droplets in the cyclodextrin solution and then solidified at room temperature for efficient extraction and convenient collection. The optimized method provided good linearity in the range of 0.01–10 mg kg−1 with limits of detection of 3.5–9.5 μg kg−1. The fortified recoveries of three pyrethroids (i.e., lambda-cyhalothrin, deltamethrin, and bifenthrin) in four cereals (i.e., rice, wheat, maize, and millet) at three levels were in the range of 77.6–101.6% with relative standard deviations of 0.6–6.6%. Overall, the proposed method can be successfully applied for the determination of pyrethroids in cereals.