Quantitative volumetric measurements of low temperature CO chemisorption on Au/ZrO2 catalysts and Fourier transform infrared measurements of adsorbed CO in well defined and controlled conditions of temperature and pressure are here presented as widely accessible and reproducible methods for determining the concentration of gold sites able to chemisorb CO on Au/ZrO2 catalysts. HRTEM analyses were also performed in order to support the validity of the measurements. (C) 2008 Elsevier B.V. All rights reserved.