Microextraction-Chromatographic Determination of Furan Derivatives in Transformer Oil

A rapid and an environmentally friendly method is developed for the microextraction of furan derivatives from transformer oil for their determination by high-performance liquid chromatography with ultraviolet spectrophotometric detection. Various hydrophilic eutectic solvents were studied as extractants to implement vortex-assisted dispersive liquid–liquid microextraction. The results indicate that a three-component eutectic solvent composed of choline chloride, acetic acid, and water achieves the highest recoveries, ranging from 85 to 96%. The rapid spontaneous phase separation eliminated the need in centrifugation. Limits of detection (3σ) were achieved between 1 and 5 µg/L.