[Determination of the concentration of free magnesium ions in hemolysates of oxygenated and deoxygenated packed human erythrocytes].

Concentrations of ionized magnesium in hemolyzates of oxygenated and deoxygenated human erythrocytes were measured directly by means of an ion exchange method. At total concentrations of hemoglobin of 8 mmol/l H2O and total magnesium of 3.6 mmol/l H2O, mean values of [Mg2+] were found to be 0.45 in the oxygenated state and 0.57 mmol/l H2O in the deoxygenated state. The difference of 0.12 +/- 0.1 mmol/l H2O is considerably smaller than corresponding literature data obtained from equilibrium calculation.