C1909

Citric acid monohydrate

ACS reagent, ≥99.0%

• Synonym(s): 2-hydroxy-1,2,3-propanetricarboxylic acid monohydrate
• Linear Formula: HOC(COOH)(CH₂COOH)₂ · H₂O
• CAS Number: 5949-29-1
• Molecular Weight: 210.14
• Beilstein/REAXYS Number: 4018641
• EC Number: 201-069-1
• MDL number: MFCD00149972
• UNSPSC Code: 12352100
• PubChem Substance ID: 24892446
• NACRES: NA.21

Properties

• grade: ACS reagent
• Quality Level: 200
• assay: ≥99.0%
• form: powder
• impurities: Substances carbonizable by hot sulfuric acid, passes test; ≤0.005% Insoluble matter
• ign. residue: ≤0.02%
• pKa: (1) 3.13, (2) 4.76, (3) 6.4
• solubility: H₂O: soluble 54 % (w/w) at 10 °C (Citric acid in water); H₂O: 59.2 % (w/w) at 20 °C (Citric acid in water); H₂O: 84.0 % (w/w) at 100 °C (Citric acid in water)
• anion traces: chloride (Cl^-): ≤0.001%; oxalate (C₂O₄^2-): passes test (limit about 0.05%); phosphate (PO₄^3-): ≤0.001%; sulfate (SO₄^2-): ≤0.002%
• cation traces: Fe: ≤3 ppm; Pb: ≤2 ppm
• SMILES string: OC(CC(O)(C(O)=O)CC(O)=O)=O.O
• InChI: 1S/C6H8O7.H2O/c7-3(8)1-6(13,5(11)12)2-4(9)10;/h13H,1-2H2,(H,7,8)(H,9,10)(H,11,12);1H2
• InChI key: YASYEJJMZJALEJ-UHFFFAOYSA-N

Description

General description

Citric acid monohydrate is an organic acid. Its molar enthalpy of solution in water has been reported to be Δ_solH_m (298.15K, m = 0.0203molkg^-1) = (29061±123)Jmol^-1. It can be produced by crystallization from mother liquor of citric acid solution at 20-25°C during citric acid synthesis. An investigation of its crystal growth kinetics indicates that growth is linearly dependent on size.

Citric acid monohydrate is an organic weak acid used as a natural preservative in food and beverage products.

Application

Citric acid monohydrate was used in the preparation of citric acid solution employed in the acetone method of ⁶⁸Ga pre-purification and radiolabeling technique.
It may be used:

• As release-modifying agent to improve the release of diltiazem hydrochloride from melt extruded Eudragit RS PO tablets.
• To prepare citrate buffer for use in the preparation of platelets for intravital microscopy.
• To prepare Tris-citrate buffer employed for the electrophoresis of bacterial enzymes.

Safety Information

• pictograms: GHS07
• signalword: Warning
• hcodes: H319,H335
• pcodes: P261 - P264 - P271 - P280 - P304 + P340 + P312 - P305 + P351 + P338
• Hazard Classifications: Eye Irrit. 2 - STOT SE 3
• target_organs: Respiratory system
• Storage Class: 11 - Combustible Solids
• wgk_germany: WGK 1
• flash_point_f: 345.0 °F - closed cup
• flash_point_c: 173.9 °C - closed cup
• ppe: dust mask type N95 (US), Eyeshields, Gloves