Title: Acid Fuchsin
CAS Registry Number: 3244-88-0
CAS Name: 2-Amino-5-[(4-amino-3-sulfophenyl)(4-imino-3-sulfo-2,5-cyclohexadien-1-ylidene)methyl]-3-methylbenzenesulfonic acid disodium salt
Synonyms: C.I. Acid Violet 19; 2-amino-a5-(4-amino-3-sulfophenyl)-a5-(4-imino-3-sulfo-2,5-cyclohexadien-1-ylidene)-3,5-xylenesulfonic acid disodium salt; acid rubin; fuchsin(e) acid; acid roseine; C.I. 42685
Molecular Formula: C20H17N3Na2O9S3
Molecular Weight: 585.54
Percent Composition: C 41.02%, H 2.93%, N 7.18%, Na 7.85%, O 24.59%, S 16.43%
Literature References: The trisulfonated derivative of rosanilin, or pararosanilin.
See: Colour Index vol. 4 (3rd ed., 1971) p 4399. Use as stain: P. W. Benoit,
Stain Technol. 48, 177 (1973); E. Hals,
Scand. J. Dent. Res. 85, 542 (1977). Mechanism of action: L. F. Nielsen
et al., Biotech. Histochem. 73, 71(1998). Brief review:
H. J. Conn's Biological Stains, R. D. Lillie, Ed. (Williams & Wilkins, Baltimore, 9th ed., 1977) pp 285-286.
Properties: Olive to dark olive-green coarse powder. Absorption max: 540-545 nm (10 mg/l of 0.01% HCl). Very sol in water, very slightly sol to insol in alcohol. Dil aq solns are purplish red. Very dil aq solns (1:10,000) are decolorized by drops of concd aq NaOH solns, but not returned by concd HCl. The decolorized soln neutralized with NaOH is called the
Andrade indicator. Changes from red to colorless at pH 12-14.
Absorption maximum: Absorption max: 540-545 nm (10 mg/l of 0.01% HCl)
Use: As pH indicator; biological stain.
