EFFECT OF PHYTATE ON THE IN-VITRO SOLUBILITY OF AL3+, CA2+, HG2+ AND PB2+ AS A FUNCTION OF PH AT 37-DEGREES-C

The effect of phytate on the solubility of Al3+ and Pb2+ has been investigated in vitro at 37 degrees C across the pH ranges 3-7 (Pb2+) and 2-5 (Al3+). For both ions minimum solubility was found when the initial metal ion: phytate ratio was in the range 5:1-3:1 across the whole pH range. For Al3+ the solubility rose sharply either side of these ratios whereas for Pb2+ solubility rose only slowly as the metal ion: phytate ratio was reduced. Hg2+ was totally soluble under all conditions tested. At pH 7 Ca2+ solubility was found to be at a minimum when the initial Ca:phytate ratio was 5:1 irrespective of the initial Ca2+ concentration.