Accessibility of trace metals,co-precipitated with calcium phytate,to soluble chelating agents

This study was designed to show the extent to which some trace metals, i.e. cadmium, copper, lead, and zinc, when co-precipitated in vitro with calcium phytate, are accessible to soluble chelating agents. Accessibility was found to range from 58% to 92%, depending on the metal, temperature, ratio of trace metal to phytate, and concentration of calcium phytate. Zinc was most sensitive to the conditions under which precipitation occurred. Less cadmium, copper, and zinc were accessible when co-precipitated at 37°C compared with co-precipitation at 20°C, and more cadmium and zinc were accessible at lower ratios of trace metal to phytate, than at higher ratios. At the lower concentration of calcium phytate, co-precipitated zinc was less accessible.