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(25-06) Henry's Law Constant in Water - Prediction of Temperature Dependency. Kühne, Ralph*,1, Ebert, Ralf-Uwe1, Schüürmann, Gerrit1, 1 UFZ Centre for Environmental Research Leipzig-Halle, Leipzig, Germany ABSTRACT- One of the key compound properties in environmental fate modelling is Henry's law constant in water, which determines the partioning between air and water. There are experimental data available, but the size of the public data pool is still moderate as compared to other compound properties. Some fairly well performing estimation methods may overcome this problem for data at 25°C. However, Henry's law constant strongly depends on temperature, and for that reason, usage of 25°C values - no matter whether experimental or calculated - will introduce significant errors into environmental fate models. An estimation method for the temperature dependency of Henry's law constant based on molecular fragments is presented. The new technique derives values within the range of environmental temperatures from known 25°C data for organic compound of several compound classes. The predictive power of the method is evaluated, and the importance for environmental modelling is demonstrated. Key words: Henry's law constant, estimation method, temperature dependency |
