The electrochemical oxidation of 1-hydroxypyrene (1-OHP) has been studied at a screen-printed carbon electrode (SPCE), by cyclic voltammetry and bulk electrolysis. Cyclic voltarnmograms exhibited two quasi-reversible pairs of peaks (designated 1a'/1c and 3a/3c) generated from the oxidation of the parent molecule. The nature of the redox reactions were further investigated by observing the effect of scan rate and pH on the voltammetric behaviour; the results suggested that the oxidation reactions giving rise to peaks 1a and 2a involved electrochemical-chemical-electrochemical (ECE) and EECE processes, respectively. Additional studies were carried out by HPLC and GC/MS and the results strongly indicated that the oxidation products were a mixture of several pyrene-quinones. In addition, liquid chromatography/mass spectroscopy (LC/MS) investigations showed that 1-OHP had undergone oxidation reactions to produce several dimers. (C) 2003 Elsevier Ltd. All rights reserved.