C.M.G. van den Berg
The inorganic species are grouped together in [M']:
[M'] = [Mn+] + [inorganic complexes]
The free metal ion concentration is related to the combined inorganic metal concentration via aM':
The fraction of metal occurring as ML is obtained by substitution for ML using the
conditional stability constant:
The fraction of M occurring as ML is calculated using its individual a-coefficient
which is obtained from
An a-coefficient is therefore simply calculated from the product of the ligand concentration and the conditional stability constant. Then:
Substitution into the mass balance for the metal:
The concentration of the free metal ion concentration can thus be calculated by
dividing the total metal concentrations by the sum of the a-coefficients.
The total metal concentration and the ligand concentrations can be determined.
The problem is now reduced to finding the concentration of L' (which is L not
complexed by M). There are two possibilities: high concentrations of L (L »M), and
the other situation of lower concentrations of 1.
9.5.1
At High Natural Ligand Concentrations
From the mass balance of L:
[L t ] = [ML] + [L']
it can be seen that [L'] "" [L t ] at high concentrations of 1. In this situation the total concentration, ([LtD can be used instead of [L']. Then
The inorganic species are grouped together in [M']:
[M'] = [Mn+] + [inorganic complexes]
The free metal ion concentration is related to the combined inorganic metal concentration via aM':
The fraction of metal occurring as ML is obtained by substitution for ML using the
conditional stability constant:
The fraction of M occurring as ML is calculated using its individual a-coefficient
which is obtained from
An a-coefficient is therefore simply calculated from the product of the ligand concentration and the conditional stability constant. Then:
Substitution into the mass balance for the metal:
The concentration of the free metal ion concentration can thus be calculated by
dividing the total metal concentrations by the sum of the a-coefficients.
The total metal concentration and the ligand concentrations can be determined.
The problem is now reduced to finding the concentration of L' (which is L not
complexed by M). There are two possibilities: high concentrations of L (L »M), and
the other situation of lower concentrations of 1.
9.5.1
At High Natural Ligand Concentrations
From the mass balance of L:
[L t ] = [ML] + [L']
it can be seen that [L'] "" [L t ] at high concentrations of 1. In this situation the total concentration, ([LtD can be used instead of [L']. Then