title: The effect of aluminum hydroxide dissolution on the bleeding of aluminum lake dyes.
abstract: The effect of pH on the bleeding of FD&C yellow No. 5 aluminum lake and FD&C red No. 40 aluminum lake was investigated. The pH-bleeding profiles corresponded to the pH-solubility profile of aluminum hydroxide. The similarity of the bleeding profiles of both lake dyes and the pH-solubility profile of aluminum hydroxide indicates that pH related bleeding, other than that occurring by competition with anions, is a result of dissolution of the aluminum hydroxide substrate. This dissolution is related to the properties of the substrate rather than to the structure of adsorbed dye.
authors.affiliation: Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, Indiana 47907.
authors.forename: A
authors.initials: A
authors.lastname: Desai
authors.forename: G E
authors.initials: GE
authors.lastname: Peck
authors.forename: J E
authors.initials: JE
authors.lastname: Lovell
authors.forename: J L
authors.initials: JL
authors.lastname: White
authors.forename: S L
authors.initials: SL
authors.lastname: Hem
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D012995:Solubility; D013645:Tartrazine / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; C005915:Allura Red AC Dye; D000536:Aluminum Hydroxide; D013645:Tartrazine