Effervescent-assisted dispersive liquid–liquid microextraction based on the solidification of floating organic droplets for the determination of fungicides in vinegar and juice

A method of effervescent-assisted dispersive liquid–liquid microextraction based on the solidification of a floating organic droplet is reported. This approach was used to measure the fungicides myclobutanil, tebuconazole and epoxiconazole in vinegar and juice. Acidic vinegar and juice reacted with the carbonate to produce effervescence in situ, which then promoted contact of the sample with the extraction solvent. The 1-dodecanol extraction solvent helped solidify the floating organic droplets and could be fully dispersed by effervescence. The extraction solvent, salt, carbonate, and extraction time were optimised. The optimal conditions were 200 μL of 1-dodecanol, 100 mg of sodium chloride, 50 mg of sodium bicarbonate, and 30 s of extraction time. The proposed method has good linearity between 10 and 1000 ng mL⁻¹. Recoveries were between 70.4% and 103.1% in different vinegar and juice samples. This method was successfully used to measure fungicides in vinegar and juice. This system is simple, fast and environmentally friendly.