CITRIC ACID, ANHYDROUS (BETA-HYDROXYTRICARBALLYLIC ACID)

CITRIC ACID, ANHYDROUS

PRODUCT IDENTIFICATION

CAS NO.

77-92-9

CITRIC ACID

EINECS NO. 201-069-1

FORMULA HOC(COOH)(CH₂COOH)₂

MOL WT. 192.14

H.S. CODE

2918.14

TOXICITY

Oral rat LD50: 3000 mg/kg

SYNONYMS Citric Acid; beta-hydroxytricarballylic acid;

Aciletten; Citretten; Citro; 2-Hydroxy-1,2,3-propanetricarboxylic acid; „ā-Hydroxytricarballylic acid; Kyselina citronova; Kyselina 2-hydroxy-1,2,3-propantrikarbonova; 2-Hydroxytricarballylic acid; Citronensäure;

SMILES fermentation from dextrose

CLASSIFICATION

GENERAL DESCRIPTION

Citric Acid (2-Hydroxy-1,2,3-propanetricarboxylic acid, in IUPAC naming) is a colourless crystalline organic compound belong to carboxylic acid family. It exists in all plants (especially in lemons and limes) and in many animal tissues and fluids. In biochemistry, it is involved in important metabolism of almost all living things; the Krebs cycle (also called citric acid cycle or tricarboxylic acid cycle), a part of the process by which animals convert food to energy. Citric acid works as a preservative ( or as an antioxidant) and cleaning agent in nature. It is commercially obtained by fermentation process of glucose with the aid of the mold Aspergillus niger and can be obtained synthetically from acetone or glycerol. It can be used as an sour taste enhancer in foods and soft drinks. The three carboxy groups lose protons in solution; resulting in the excellent pH control as a buffer in acidic solutions. It is used as a flavouring, stabilizing agent and acidulant (to control acidity) in food industry, in metal-cleaning compositions as it chelates metals. Citric acid is available in forms of anhydrous primarily and in monohydrate, the crystallized form from water. The hydrated form will be converted to the anhydrous form above 74 C. Citrate is a salt or ester of citric acid. Citrates are formed by replacing the acidic one, two, or all three of the carboxylic hydrogens in citric acid by metals or organic radicals to produce an extensive series of salts, esters, and mixed (double) salts. Cirrates are used in food, cosmetics, pharmaceutical and medicine industries as well as in plastic industry; nutrient or food additives having functions of acidity regulator, sequestering and stabilizing agent, antioxidants synergist, firming agent; anticoagulant for stored whole blood and red cells and also for blood specimens as citrates chelate metal ions and saline cathartics, effervescent medicines; high boiling solvent, plasticizer and resin for food contact plastics.

EXAMPLES OF NATURALLY OCCURRING CARBOXYLIC ACIDS
(excluding fatty acids)

Pyruvic acid	Lactic Acid	Cholic acid	Nicotinic acid

metabolic intermediate	metabolic intermediate	from bile	vitamin B

Citric acid	Malic Acid	Biotin	Abietic acid

in plants	in fruits	cell growth factor	pine rosin

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE White crystals

MELTING POINT 153 - 154 C

BOILING POINT Decomposes

SPECIFIC GRAVITY 1.665

SOLUBILITY IN WATER 59.2%

pH 2.2 (0.1 N sol).

VAPOR DENSITY

AUTOIGNITION

1011 C

NFPA RATINGS

Health: 0 Flammability: 1 Reactivity: 0

REFRACTIVE INDEX

FLASH POINT

100 C

STABILITY Stable under ordinary conditions

APPLICATIONS

Food, Beverages, Flavour enhancer, Colouring, Preservative, Detergents, Cleaners, Pharmaceuticals, Cosmetics, Industrial and Chemical processing

SALES SPECIFICATION

BIBLIOGRAPHY

FCC/USP/BP

APPEARANCE

clear or white crystalline powder

ASSAY

99.5% min

CLARITY OF SOLUTION

4 NTU

SULPHATE

150ppm max

CHLORIDE

50ppm max

IRON

5ppm max

READILY CARBONIZABLES

Pass test

OXALATE

350ppm max

CALCIUM

200ppm max

ARSENIC

3ppm max

HEAVY METALS (as Pb)

10ppm max

TRANSPORTATION

PACKING

25kgs in bag

HAZARD CLASS Not regulated

UN NO.

OTHER INFORMATION

Hazard Symbols: XI, Risk Phrases: 37/38-41, Safety Phrases: 26-36/37/39