SDS Volume (116)

Volume 20. Halogenated Benzenes, Toluenes and Phenols with Water, p 239

Original Measurements

Blackman, G. E.; Park, M. H.; Garton, G.; Arch. Biochem. Biophys. 1955, 54(1), 55-71.

Variables:

Temperature: 25 °C
Acidity: 5.1

Prepared by:

F.W. Getzen

Method/Apparatus/Procedure:

Equilibrium was established by mixing the solute with distilled water buffered with $\ce{KH2PO4}$ at a pH of 5.1 in a glass-stoppered bottle suspended in a thermostat bath at 25 °C. The sample was shaken periodically for two days with appropriate adjustment of pH to 5.1. After the pH became stabilized (usually about one week), the sample was equilibrated for an additional two weeks to assure saturation. Concentration was determined either directly by spectrophotometric techniques or by a colorimetric method based upon that given by [1] in which suitable colorizing agents [2,3] were added either to the saturated solution or to an appropriately diluted solution to yield an optical density proportional to the solute concentration. Concentration was obtained as the average of three replicate measurements.

Source and Purity of Materials:

1. Probably a commercial reagent.
2. Distilled water.

References

¹ Snell, F. D.; Snell, C. T. 'Colorimetric Methods of Analysis', Vol. II; Chapman and Hall: London, England, 1936.
² Folin, O.; Denis, W.; J. Biol. Chem. 1912, 12, 239.
³ Folin, O.; Ciocalteu, V.; J. Biol. Chem. 1927, 73, 627.