title: Identification of anthraquinone coloring matters in natural red dyes by electrospray mass spectrometry coupled to capillary electrophoresis.
abstract: Capillary electrophoresis with UV/visible diode-array detection (DAD) and electrospray mass spectrometric (ESI-MS) detection were used for the identification of anthraquinone color components of cochineal, lac-dye and madder, natural red dyestuffs often used by ancient painters. For the purpose of such analysis, ESI-MS was found to be a much more appropriate detection technique than DAD one owing to its higher sensitivity (detection limits in the range 0.1-0.5 micro g ml(-1)) and selectivity. The method developed made it possible to identify unequivocally carminic acid and laccaic acids A, B and E as coloring matters in the examined preparations of cochineal and lac-dye, respectively. In madder, European Rubia tinctorum, alizarin and purpurin were found. The method allows the rapid, direct and straightforward identification and quantification of components of natural products used in art and could be very helpful in restoration and conservation procedures.
authors.affiliation: Faculty of Chemistry, Department of Analytical Chemistry, Warsaw University of Technology, ul. Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Puchalska
authors.forename: Magdalena
authors.initials: M
authors.lastname: Orlińska
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Ackacha
authors.forename: Kasia
authors.initials: K
authors.lastname: Połeć-Pawlak
authors.forename: Maciej
authors.initials: M
authors.lastname: Jarosz
mesh_terms: D000818:Animals; D000880:Anthraquinones / Q000737:chemistry* / Q000302:isolation & purification*; D002329:Carmine / Q000031:analogs & derivatives* / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry* / Q000302:isolation & purification; D019075:Electrophoresis, Capillary / Q000379:methods*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000880:Anthraquinones; D004396:Coloring Agents; D010936:Plant Extracts; D002329:Carmine