A colorimetric technique, originally developed for methyl iso butyl carbinol (MIBC) based on the Komarowsky reaction, has been extended to a wide range of common mineral flotation frothers. The procedure, which is briefly described, is suited to on-site determination as shown in a series of industrial case studies. Some observations described include: distribution of frother down a bank and between pulp and froth; evidence of alcohol. contaminants; and mass balancing. The ability to monitor frother will help interpret cell hydrodynamics and should help optimize the type, amount and location of frother addition. (0 2007 Elsevier Ltd. All rights reserved.