Abstract: The concept of the general a_N index (GAI) has been derived from the a_N index, takinginto account the presence of the hetero atoms. In this paper the GAIs were calculated forsome acidic and neutral organophosphorus extractants. The correlations between the GAIs andthe physicochemical properties of these compounds have been investigated with satisfactoryresults, such as R_f value, corrected retention time, retention value in paper chromatography,mobility value in paper electrophoresis and molar refraction value.

Key words: acidic organophophorus extractant, neutral organophophorus extractant, genaral aN index, correlation analysis