  a citrate is a derivative of citric acid; that is, the salts, esters, and the polyatomic anion found in solution. an example of the former, a salt is trisodium citrate; an ester is triethyl citrate. when part of a salt, the formula of the citrate ion is written as c6h5o73â or c3h5o(coo)33â. ==other citric acid ions== since citric acid is a multifunctional acid, intermediate ions exist, hydrogen citrate ion, hc6h5o72â and dihydrogen citrate ion, h2c6h5o7â. these may form salts as well, called acid salts. ==acidity== salts of the hydrogen citrate ions are weakly acidic, while salts of the citrate ion itself (with an inert cation such as sodium ion) are weakly basic. ==buffering== as a weak acid, citrate can be used as a component in buffer solutions, including the commonly used ssc 20x hybridization buffer.maniatis, t.; fritsch, e. f.; sambrook, j. 1982. molecular cloning: a laboratory manual. cold spring harbor laboratory, cold spring harbor, ny. this buffer uses sodium citrate and sodium chloride to maintain a neutral 7.0 ph. other buffers may use a mixture of sodium citrate and citric acid â canonical buffer tables compiled for biochemical studies describe solutions of citrate and acid for buffer phs of between 3.0 and 6.2. ==chelating== citric acid can act as a mild chelating agent; citrate, usually in the form of trisodium citrate, may be given as an anticoagulant, because it chelates calcium ions, and therefore inhibits coagulation. another application is in the form of iron(ii) citrate as a nutritional supplement. here, the benefit is the solubility as a chelate of the otherwise mostly insoluble iron. ==metabolism==  citrate is an in
Carboxylate_anions Citrates Citric_acid_cycle