Application of specific ion interaction theory and parabolic models for the molybdenum(VI) and tungsten(VI) complexes with NTA and IDA at different ionic strengths

The interaction of nitrilotriacetic acid (NTA) and iminodiacetic acid (IDA) with tungsten(VI) (pH 7.5) and molybdenum(VI) (pH 6.00) has been studied in aqueous solutions at 25 °C, and different ionic strengths (0.1 < I (mol dm−3) < 1.0 for NaClO4) by a combination of potentiometric and UV spectroscopic(260–270 nm) measurements. Dependence on ionic strength was taken into account by using the Bronsted–Guggenheim–Scatchard specific ion interaction theory (SIT) and parabolic model. The data included in this work, together with some previously published data, make it possible to calculate parameters for dependence on ionic strength by using the aforementioned models.