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|Systematic IUPAC name
3D model (JSmol)
|E number||E574 (acidity regulators, ...)|
CompTox Dashboard (EPA)
|Molar mass||196.16 g/mol|
|Melting point||131 °C (268 °F; 404 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
In aqueous solution at neutral pH, gluconic acid forms the gluconate ion. The salts of gluconic acid are known as "gluconates". Gluconic acid, gluconate salts, and gluconate esters occur widely in nature because such species arise from the oxidation of glucose. Some drugs are injected in the form of gluconates.
The chemical structure of gluconic acid consists of a six-carbon chain, with five hydroxyl groups positioned in the same way as in the open chained form of glucose, terminating in a carboxylic acid group. In aqueous solution, gluconic acid exists in equilibrium with the cyclic ester glucono delta-lactone.
Gluconic acid occurs naturally in fruit, honey, and wine. In 1929 Horace Terhune Herrick developed a process for producing the salt by fermentation. As a food additive (E574), it is now known as an acidity regulator.
The gluconate anion chelates Ca2+, Fe2+, Al3+, and other metals, including lanthanides and actinides. It is also used in cleaning products, where it dissolves mineral deposits, especially in alkaline solution.
Calcium gluconate, in the form of a gel, is used to treat burns from hydrofluoric acid; calcium gluconate injections may be used for more severe cases to avoid necrosis of deep tissues, as well as to treat hypocalcemia in hospitalized patients. Gluconate is also an electrolyte present in certain solutions, such as "plasmalyte a", used for intravenous fluid resuscitation. Quinine gluconate is a salt of gluconic acid and quinine, which is used for intramuscular injection in the treatment of malaria.
Gluconate is used as a concrete admixture (retarder) to slow down the cement hydration reactions and to delay the cement setting time. It allows so a longer time to place the concrete or to spread the cement hydration heat on a longer period of time to avoid too high temperature and the resulting cracks. Retarders are mixed to concrete when the weather temperature is high or to cast large and thick concrete slabs in successive and sufficiently well mixed layers.
Dr. Horace T. Herrick (U. S. Department of Agriculture) told of experiments aiming to produce tartaric acid from mold. They did not succeed in their aim, but a way was found of procuring gluconic acid. This acid formerly cost $100 per lb., can now be made for less than 35¢. It can be used in dyestuff manufacture at the new price; also, to make calcium gluconate, valuable medicinally in the treatment of hemorrhages.