METHOD FOR MICROEXTRACTION-CHROMATOGRAPHIC DETERMINATION OF CONTENT OF FURAN DERIVATIVES IN TRANSFORMER OIL Russian patent published in 2025 - IPC G01N30/06 

FIELD: analytical chemistry.

SUBSTANCE: method for microextraction-chromatographic determination of content of furan derivatives in transformer oil involves extraction of furan derivatives from transformer oil by liquid-liquid microextraction, realized with mechanical mixing of phases of sample and extractant, subsequent separation of phases due to destruction of emulsion "transformer oil-extractant" in the absence of external mechanical action, determination of content of furan derivatives in the extract phase, including 5-hydroxymethyl-2-furfural, furfuryl alcohol, 2-furfural, 2-acetylfuran and 5-methyl-2-furfural. Solvents forming the mobile phase of the liquid chromatograph system are water and methyl alcohol. Extractant used is a eutectic solvent consisting of choline chloride, acetic acid and water with weight content of said components of 51-61, 19-29 and 10-20%, respectively, taken for extraction in volume of 0.1-0.2 cm^3. Extraction time is 1-2 minutes, and the lower limit of the range of determined concentrations of furan derivatives in transformer oil is 0.005 mg/kg.

EFFECT: high efficiency and sensitivity of analysis.

1 cl, 4 tbl