[Determination of stability constants of metal complexes by on-column derivatization reversed phase high performance liquid chromatography].
The stability constant of metal complexes is an important chemical parameter. There are many methods for its determination, but few analyst has calculated it with high performance liquid chromatography (HPLC). In the present paper a new model for determining the stability constant of metal complexes with on-column derivatization reversed phase HPLC has been proposed where complexation forming reactions are taking place in the mobile phase. Based on the retention mechanism of neutral complexes, the equation for calculation is deduced. It has been applied to some cations (Hg2+, Pb2+, Ni2+, Cu2+, Ag+, Hg+)-DDTC complexes. The results are in agreement with those given in the literature. Then, a simple, practical and rapid graphic method is studied for monovalent metal complexes. The stability constants can be obtained simply as the quotient of the line slope and the axis intercept of the linear dependence. The relations derived in this paper may be used not only for calculating the stability constants from chromatographic measurements but also for optimizing the process of separation based on the values of the stability constants available in literature.
Wang
X
X
Research Center of Physical and Chemical Analysis, Hebei University, Baoding, 071002.
Fu
C
C
D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D056148:Chromatography, Reverse-Phase / Q000295:instrumentation / Q000379:methods*; D056831:Coordination Complexes / Q000737:chemistry*
D056831:Coordination Complexes