Total reduced sulfurs quartet (H2S, CH3SH, CH3SCH3 and CH3SCH3) is part of a well-known environmental problem afflicting pulp mills exploiting the Kraft mill sulfate-pulp process. Utilization of ferric chelate complex of trans-1,2-cyclohexanediaminetetraacetic acid (CDTA) for the oxidative scrubbing of H2S and CH3SH in Kraft mill streams is beneficial from the standpoints of iron protection against precipitation and oxygen-mediated regenerative oxidation of the ferrous chelate CDTA. The remaining two sulfur-bearing compounds, considered not oxidizable by CDTA-Fe(III), undergo only physical absorption in such solutions, so their solubility in aqueous CDTA-Fe(III) alkaline solutions is a crucial parameter for designing the complete scrubbing-absorption process. This investigation was carried out to determine the Henry's law constants of dimethyldisulfide (DMDS) in pure water, in aqueous iron-free CDTA solutions and CDTA-Fe(III) complex solutions using the static headspace method with an estimated accuracy of 2%. Experiments with aqueous solutions of chelate concentrations varying between 38 and 300 mol m(-3) were carried out at temperatures between 298 and 333 K and atmospheric pressure. It was shown that DMDS solubility decreases with increasing temperature for all systems and is not much influenced by the CDTA concentration and solution pH. (c) 2005 Elsevier B.V. All rights reserved.