In this contribution we report on kinetic investigations of the Dushman reaction at concentrations relevant to mixing studies in microstructured cyclone type mixers. The investigations were carried out under incomplete mixing. With this approach the kinetic investigations are as close as possible to the conditions of the corresponding mixing investigations, but no information on the absolute rate of the Dushman reaction is obtained. Our data suggest reaction orders (I-: 2; IO3-: 1; H+: 1.3) close to those, typically assumed for mixing studies. No significant influence of the ionic strength could be found. Previous assumptions on the influence of the ionic strength neglected the basic nature of the sulfate ion. The use of perchloric acid instead of sulfuric acid, commonly employed in mixing studies, yields far higher optical densities of the resulting solutions, suggesting higher local H+ concentrations for the perchloric acid case. (C) 2013 Elsevier Ltd. All rights reserved.