Reference

A polarographic study of carminic acid

A polarographic study of carminic acid. Li, Nanqiang; Min, Jing (Dep. Chem., Peking Univ., Beijing, Peop. Rep. China). Wuli Huaxue Xuebao, 2(6), 549-53 (Chinese) 1986. CODEN: WHXUEU. DOCUMENT TYPE: Journal CA Section: 72 (Electrochemistry) Section cross-reference(s): 66 In 0.2 mol/L acetate buffer soln. at pH 4.2-4.5, carminic acid [1260-17-9] exhibited a reversible adsorptive wave in a single-sweep polarogram. The electrode reaction was: (H2L-)ads + 2H+ + 2e J (H2L'-)ads, where H2L- and H2L'- were the anthraquinone and dihydroanthraquinone ions of carminic acid, resp. On the surface of a Hg electrode, the adsorption of carminic acid obeyed the Frumkin adsorption isotherm. The adsorption coeff. 1260-17-9 and 106984-65-0 are also in the experiment. (b = 7.0 ′ 106), the interaction factor (v = -0.92), the amt. of satd. adsorption (Gs = 1.39 ′ 10-10 mol/cm2) and the adsorptive rate const. (kads = 9.7 ′ 10-8 cm/s) were detd. .

Separation of carminic acid

Separation of carminic acid. Stanek, Jan; Hermankova, Vera; Ineman, Vaclav; Kefurtova, Zdena; Jary, Jiri (Vysoka Skola Chemicko-Technologicka, Czech.). Ger. Offen. DE 3319756 A1 8 Dec 1983, 10 pp. (German). (Germany). CODEN: GWXXBX. CLASS: IC: C09B067-54; C09B061-00. APPLICATION: DE 83-3319756 31 May 1983. PRIORITY: CS 82-4079 2 Jun 1982. DOCUMENT TYPE: Patent CA Section: 41 (Dyes, Organic Pigments, Fluorescent Brighteners, and Photographic Sensitizers) Section cross-reference(s): 17 The aq. soln. obtained by extn. 89190-63-6 and 1260-17-9 which are cas registry numbers are also used here. of nopal is adjusted with acid to pH 0-7 and fed to a water-satd. column of powd. polyamide, after which the column is washed with water at pH 0-7 to remove impurities and then treated with aq. base, e.g. NH4OH or NaOH, to desorb carminic acid (I) [1260-17-9] as a salt contg. ￡15% impurities. The I salt soln. is adjusted to pH 0-7 with acid and fed to a column of styrene-divinylbenzene copolymer, e.g. Ostion SP-2, and the column is washed with water to remove residual impurities and salt and then treated with org. solvent to elute I of high purity (97-99.5%). .