DETERMINATION OF FURANIC COMPOUNDS IN INSULATING OIL BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY USING ATMOSPHERIC-PRESSURECHEMICAL-IONIZATION

A method has been developed to determine furanic compounds in insulati ng oil matrix using liquid chromatography/mass spectrometry with atmos pheric pressure chemical ionization. The examined samples were provide d from model experiments and also from several high voltage functionin g transformers. To increase sensitivity of the method six furanic comp ounds (determined by model experiments) were quantified by selected io n monitoring, and quantitation was based on the marker peaks. Oil samp les were prepared using solid phase extraction. The results are suitab le for evaluation of model experiments and also to solve problems of c alibration. From extracts of oil samples taken from functioning transf ormers cellulose depolymerization products have been identified, and t heir amounts were found to be valuable in assessing the condition of t he transformer (fault diagnosis), (C) 1998 John Wiley & Sons, Ltd.