Properties: Crystals (usually plates, sometimes needles, monoclinic system). Pleasant, sharp acidic taste. mp 190-192° (some dec). d 1.65. [a]D25 +20.5 to +21.5° (c = 1 in water); [a]D23 +48° (c = 1 in methanol). pH = 3 (5 mg/ml); pH = 2 (50 mg/ml); pK1 = 4.17; pK2 = 11.57. uv max at pH 2: 245 nm (E1%1cm 695); at pH 6.4: 265 nm (E1%1cm 940). Redox potential (first stage): E10 +0.166 V (pH 4). One gram dissolves in about 3 ml water, 30 ml alc, 50 ml abs alc, 100 ml glycerol, 20 ml propylene glycol. Soly in water: 80.0% at 100°; 40.0% at 45°. Insol in ether, chloroform, benzene, petr ether, oils, fats, fat solvents. Strong reducing agent. Stable to air when dry; aq solns are rapidly oxidized by air.
Melting point: mp 190-192° (some dec)
pKa: pK1 = 4.17; pK2 = 11.57
Optical Rotation: [a]D25 +20.5 to +21.5° (c = 1 in water); [a]D23 +48° (c = 1 in methanol)
Absorption maximum: uv max at pH 2: 245 nm (E1%1cm 695); at pH 6.4: 265 nm (E1%1cm 940)
Density: d 1.65
Derivative Type: Calcium hypophosphite
Additional Names: Asphocalcium
Trademarks: Calscorbat (Aerocid)
Percent Composition: C 25.72%, H 3.24%, Ca 14.30%, O 45.68%, P 11.05%
Derivative Type: Calcium salt
CAS Registry Number: 5743-27-1
Additional Names: Calcium ascorbate
Percent Composition: C 36.93%, H 3.62%, Ca 10.27%, O 49.19%
Literature References: Prepn: Ruskin, Merrill, Science
105, 504 (1947).
Properties: Dihydrate, triclinic crystals, [a]D20 +95.6° (c = 2.4). Freely sol in water. Practically insol in methanol, ethanol.
Optical Rotation: [a]D20 +95.6° (c = 2.4)
Derivative Type: Sodium salt
CAS Registry Number: 134-03-2
Additional Names: Sodium ascorbate
Trademarks: Cenolate (Abbott); Xitix (Woelm)
Percent Composition: C 36.38%, H 3.56%, Na 11.60%, O 48.46%
Literature References: Prepn: Holland,
US
2442005 (1948).
Properties: Minute crystals, dec 218°. [a]D20 +104.4°. Soly in water: 62 g/100 ml at 25°; 78 g/100 ml at 75°.
Optical Rotation: [a]D20 +104.4°
Use: As antimicrobial and antioxidant in foodstuffs.
Therap-Cat: Vitamin (antiscorbutic).
Therap-Cat-Vet: Vitamin (antiscorbutic).
Keywords: Vitamin/Vitamin Source; Vitamin C.
产品链接: 50-81-7››