Sequestration

Name:
Sequestration
Detailed information:
The formation of a coordination complex by certain phosphates with metallic ions in solution so that the usual precipitation reactions of the latter are prevented. Thus, calcium soap precipitates are not produced from hard water treated with certain polyphosphates and metaphosphates (these polyphosphates are often improperly referred to as hexametaphosphates). The term sequestration may be used for any instance in which an ion is prevented from exhibiting its usual properties due to close combination with an added material. Two groups of organic sequestering agents (chelates in these examples) of economic importance are the aminopolycarboxylic acids such as ethylenediaminetetraacetic acid, and the hydroxycarboxylic acids such as gluconic, citric, and tartaric acids. In the food industry sequestering agents aid in stabilizing color, flavor, and texture.See Chelate; Coordination Compound; complex.