Heats of preferential adsorption of chelates

A method employing a flow calorimeter for determining heats of preferential adsorption of certain organic chelates of metals from organic solutions is described. Experimental heats of adsorption are correlated with the chromatographic behaviour of the chelates and it is shown that irreversible retention on a column occurs when the heat is greater than 6 kcal mole^-1 for the first stage of the two-stage adsorption pro cess. The special case of the 2-methyl-8-quinoline chelate of copper(II) and its elution with solutions of the reagent is examined in more detail: heats of preferential adsorption decrease with increasing concentrations of reagent and the optimum experimental concentration can be predicted from the heat results.