Abstract
The adsorption constant (K) of fungicidal dialkyl 1, 3-dithiolan-2-ylidenemalonates and related compounds with a soil sample from Osaka district was determined at 25°C. The value of K increases regularly with increasing chain length of the alkyl groups. The log K value was nicely correlated with the hydrophobic parameter, log P, where P is the partition coefficient determined with the 1-octanol-water system. The adsorption process of these compounds seems to be governed by the hydrophobic interaction with the soil components. The mobility of these compounds in the soil with water was also determined using soil-column chromatography. The log (mobility constant) value was linearly related to log K with a negative slope. The stronger the soil adsorption is, the slower is the movement in the soil layer.
