[An ion exchange method to determine free metal concentrations, adapted for use in biological fluids: methods and determination of (Mg2+)].
An ion exchange method for measuring concentrations of free (ionized) metal ions and its application to the determination of [Mg2+] is described. A surface sulfonated polystyrene material is used as the "twodimensional" cation exchanger. The sample-volume is 1 ml. About 50 determinations can be performed within 1 hr having a standard error of +/- (2-4)% in the optimal range of measurement. Advantages and disadvantages of the method compared with other ones are demonstrated and discussed. Free Mg2+ ion concentrations were measured in solutions containing pyrophosphate as well as haemoglobin and compared with those which were determined by equilibrium calculation or ultrafiltration.
D002411:Cation Exchange Resins; D011756:Diphosphates; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000032:analysis*; D008670:Metals / Q000032:analysis; D010108:Oxyhemoglobins; D012996:Solutions
D002411:Cation Exchange Resins; D011756:Diphosphates; D008670:Metals; D010108:Oxyhemoglobins; D012996:Solutions; D008274:Magnesium
Eine Ionenaustauschmethode zur Bestimmung freier Metallionenkonzentrationen, geeignet zur Anwendung in biologischen Flüssigkeiten: Methodik und Bestimmung von (Mg2+)