Ionization constants of a soil fulvic acid

摘要

The ionization constants of a soil extracted fulvic acid were obtained analysing the potentiometric titration curves at different fulvic acid concentrations (20, 40 and 80 mg/L) and different background electrolyte concentrations from 5 10(-3) M to 1.0 M, The results confirm the presence of two types of acidic groups with ionization constants in the range 4.27 < pK(1) < 4.84 and 7.85 < pK(2) < 8.81, respectively. [References: 8]