Pulsed amperometric detection of furan compounds in transformer oil

The failure of high voltage transformers can result in significant cost and supply implications to both power supplier and consumer alike and in extre me cases may result in explosion, serious injury or death. Transformer fail ure can be predicted by measuring furanics present in the oil, produced by the thermolytic breakdown of cellulosidic insulators. Failing units can hav e furanic levels of up to 10 mug ml(-1). The use of pulsed amperometric det ection (PAD) to measure furanics in transformer oils in real time is report ed here. Oils were examined by pre-extraction or direct suspension in aqueo us measurement solution or by solubilisation and direct PAD measurement in organic solvents. Linear relationships between PAD response and furanic con centration was found for 2-furaldehyde and furfuryl alcohol (F-OH) across t he range of 0-10 mug ml(-1), with PAD proving most sensitive to the latter compound. PAD was performed directly in the organic phase in t-butanol with 0.1 M tetramethyl ammonium hydroxide, with aged oils containing >2 mug ml( -1) of 2-furaldehyde yielding data within close agreement (<9%) of a standa rd chromatographic method. The simplicity and rapidity of this method offer s the power transmission industry a means of monitoring furanic levels in t ransformers in real time, thereby reducing the risk of uncontrolled transfo rmer failure. (C) 2001 Elsevier Science B.V. All rights reserved.