Citric acid

Products Name: Citric acid

Molecular Formula:      C6H8O7

CAS No.: 77-92-9

Product Description:
Citric acid is a weak organic acid, and it is a natural preservative and is also used to add an acidic, or sour, taste to foods and soft drinks. In biochemistry, it is important as an intermediate in the citric acid cycle and therefore occurs in the metabolism of virtually all living things. It can also be used as an environmentally benign cleaning
agent and acts as an antioxidant and a lubricant.

Citric acid exists in greater than trace amounts in a variety of fruits and vegetables,
most notably citrus fruits. Lemons and limes have particularly high concentrations of the acid; it can constitute as much as 8% of the dry weight of these fruits (1.44 and 1.38 grams per ounce of the juices, respectively[3]). The concentrations of citric acid in citrus fruits range from .005 mol/L for oranges and grapefruits to .030 mol/L in lemons and limes. These values vary depending on the circumstances in which the fruit was grown.

Applications:

In 2007 world wide annual production stands at approximately 1,700,000 MT. More than 50%
of this volume is being produced in China. More than 50% is being used as acidulent in beverages and some 20% in other food applications. 20% is being used for detergent applications and 10% for other non-food related applications like cosmetics, pharma and
in the chemical industry.

·Food additive
As a food additive, citric acid is used as a flavoring and preservative in food and beverages, especially soft drinks. It is denoted by E number E330. Citrate salts of various metals are used to deliver those minerals in a biologically available form in many dietary supplements. The buffering properties of citrates are used to control pH in household cleaners and pharmaceuticals. In the United States the purity requirements for citric acid as a food additive are defined by the Food Chemical Codex (FCC), which is published by the United States Pharmacopoeia (USP).

·Water softening
Citric acid's ability to chelate metals makes it useful in soaps and laundry detergents.
By chelating the metals in hard water, it lets these cleaners produce foam and work
better without need for water softening. In a similar manner, citric acid is used to regenerate the ion exchange materials used in water softeners by stripping off the accumulated metal ions as citrate complexes.The saturation point for citric acid and
water is 59%.

·Others
Citric acid is used in biotechnology and the pharmaceutical industry to passivate high-purity process piping (in lieu of using nitric acid). Nitric acid is considered hazardous
to dispose once used for this purpose, while citric acid is not.[citation needed]

Citric acid is the active ingredient in some bathroom and kitchen cleaning solutions.
A solution with a 6% concentration of citric acid will remove hard water stains from
glass without scrubbing. In industry it is used to dissolve rust from steel.

Citric acid is commonly used as a buffer to increase the solubility of brown heroin.
Single-use citric acid sachets have been used as an inducement to get heroin users to exchange their dirty needles for clean needles in an attempt to decrease the spread of
AIDS and hepatitis.
Other acidifiers used for brown heroin are ascorbic acid, acetic acid, and lactic acid;
in their absence, a drug user will often substitute lemon juice or vinegar.

Citric acid is one of the chemicals required for the synthesis of HMTD, a highly heat-, friction-, and shock-sensitive explosive similar to acetone peroxide. For this reason, purchases of large quantities of citric acid may rouse suspicion of potential terrorist activity.[citation needed]

Citric acid can be added to ice cream to keep fat globules separate, and can be added to recipes in place of fresh lemon juice as well. Citric acid is used along with sodium bicarbonate in a wide range of effervescent formulae, both for ingestion (e.g., powders
and tablets) and for personal care (e.g., bath salts, bath bombs, and cleaning of grease).

Citric acid is commonly employed in wine production as a substitute or improver where fruits containing little or no natural acidity are used. It is mostly used for inexpensive wines due to its low cost of production.

Citric acid can be used in shampoo to wash out wax and coloring from the hair.
It is notably used in the product "Sun-in" for bleaching, but is generally not recommended due to the amount of damage it causes.[citation needed]

Citric acid is also used as a stop bath in photography. The developer is normally alkaline, so a mild acid will neutralize it, increasing the effectiveness of the stop bath when compared to plain water.

Citric acid is used as one of the active ingredients in the production of anti-viral tissues.

Citric acid may be used as the main ripening agent in the first steps of making mozzarella cheese.

Citric acid was the first successful eluant used for total ion-exchange separation of the lanthanides, during the Manhattan Project in the 1940s. In the 1950s, it was replaced by
the far more efficient EDTA.

Citric acid is used as a good alternative to nitric acid in the process of stainless steel passivation (ie "Citrisurf")

Citric acid can be used as a delay to prompt natural cement.
It can delay the very rapid setting time substantially.