Nomenclature
CAS number: 4548-53-2
3-[(2,4-Dimethyl-5-sulfophenyl)azo]-4-hydroxy-1-naphthalenesulfonic
acid disodium salt; FD & C Red No. 4; C.I. Food Red 1; C.I. 14700.
C
18H
14N
2Na
2O
7S
2; mol wt 480.42.
C 45.00%, H 2.94%, N 5.83%, Na 9.57%, O 23.31%, S 13.35%.
Description and references
Azo dye. Prepn: E. N"olting, O. Kohn, Ber. 19, 137 (1886). Metabolism:
J. L. Radomski, T. J. Mellinger, J. Pharmacol.
Exp. Ther. 136, 259 (1962). Toxicity studies:
F. C. Lu, A. Lavalle, Can. Pharm. J. 97, 30 (1964); K. J. Davis et al., Toxicol. Appl. Pharmacol. 8, 306
(1966). Determn in maraschino cherries: R. E. Draper, J. Assoc. Off. Anal. Chem. 56, 703 (1973); HPLC determn in lipstick: L. Gagliardi et al., J. Chromatogr. 394, 345 (1987). Review: IARC Monographs 8, 207-214 (1975). See also: Colour Index vol. 4 (3rd ed.,
1971) p 4068.
Properties
Red crystals. Absorption
max (0.02 N CH3COONH4): 500 nm. Sol in water;
slightly sol in ethanol. Insol in vegetable oils. Deep red soln
in conc H2SO4, changing to red ppt on dilution.
Orange soln in conc HNO3, turning yellow. LD50 orally in rats: >2 g/kg (Lu, Lavalle).Use
Dye in externally applied drugs, cosmetics; food
colorant in maraschino cherries.