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.