Aluminium speciation studies in biological fluids. A new investigation of aluminium hydroxide equilibria under physiological conditions

Aluminium is prone to hydrolyse within a large range of physiological pH. Although this phenomenon has drawn much attention in the recent past, no reliable hydroxide formation constants have been produced so far that can be applied to physiological conditions of ionic strength and temperature. Prior to future aluminium–ligand equilibrium studies, aluminium hydroxide formation at 37 °C in aqueous NaCl (0.15 mol dm–3) has been investigated. The following species have been characterized: [Al(OH)]2+, Al(OH)3, [Al(OH)4]–, [Al3(OH)11]2–, [Al6(OH)15]3+, and [Al8(OH)22]2+.