Only one measurement, that of Blackman et al. (1), was found in the literature for the solubility of 2,6-dichloro-4-methylphenol in water. The determination was part of a study to provide some insight into the mode of biological action of substituted phenols as related to differences in physical properties.
Saturation was established at 298.15 K over a 3-4 week period, a reasonably sufficient time interval for saturation equilibrium. The system pH was adjusted to 5.1 by addition of small amounts of KH2PO4 buffer. Concentration determinations were accomplished either by direct spectrophotometric techniques or, indirectly, by colorimetry using added colorizing reagents. The colorimetry method was based upon a standard procedure in which suitable colorizing agents were added either to the saturated phenol solution or to appropriately diluted solutions to yield an optical density proportional to the phenol concentration. A standardized curve obtained from measurements using known phenol concentrations was required for the determinations.
The concentration was obtained from three replicate measurements as an average value. Where both analytical procedures were used for the same solute, the agreement between the measurements of concentration was within 5 percent.
No mention was made of further purification of the solute reagent (probably a commercial product). The water was probably distilled. The ionic effects of the buffer upon the saturation value can be taken as minimal. However, it must be noted that pH does affect the solubility of protolytic solutes such as 2,6-dichloro-4-methylphenol. In this work, it can be assumed that the reported solubility refers, within experimental error, to the saturation value at the pH which exists for the saturated solution of 2,6-dichloro-4-methylphenol alone, in water.
The uncertainty in the single reported value can be assumed to be as large as ±5 percent. The following solubility value for 2,6-dichloro-4-methylphenol in water is tentative: