title: Micellar electrokinetic chromatography method for the determination of several natural red dyestuff and lake pigments used in art work.
abstract: The identification of organic colorants used in artistic paintings is an important information source for reconstructing the working techniques found in a particular work and for defining a programme for the restoration and conservation of the painting. In this work, sodium dodecyl sulfate (SDS) was used as a surfactant in micellar electrokinetic chromatography (MEKC) for separating a broad range of red organic pigments, based on their colouring matters: madder (colouring matters: alizarin, quinizarin and purpurin), cochineal (colouring matter: carminic acid), red sandalwood (colouring matter: santalin), brazilwood (colouring matter: brazilin), lac dye (colouring matter: laccaic acid) and dragon's blood (colouring matter: dracorhodin). The running electrolyte used was 20 mM borax (pH 9), containing 20 mM SDS and 10% acetonitrile as organic modifier. Separation was carried out by applying a +20 kV voltage at the injection end, 25 degrees C and 214 nm/254 nm as detection wavelengths. All colorants were separated within less than 13 min with a good baseline resolution. The method was applied to the analysis of paint samples obtained from the Diocesan Museum of Holy Art of Bilbao.
authors: Departamento de Pintura, Facultad de Bellas Artes, Universidad del País Vasco/EHU, Apdo. 644, E-48080 Bilbao, Spain. itxaso.maguregui@ehu.es
authors: M I
authors: MI
authors: Maguregui
authors: R M
authors: RM
authors: Alonso
authors: M
authors: M
authors: Barandiaran
authors: R M
authors: RM
authors: Jimenez
authors: N
authors: N
authors: García
mesh_terms: D001154:Art; D001391:Azo Compounds / Q000302:isolation & purification; D001578:Benzopyrans / Q000302:isolation & purification; D029911:Caesalpinia / Q000737:chemistry; D002329:Carmine / Q000031:analogs & derivatives / Q000302:isolation & purification; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D003116:Color; D004396:Coloring Agents / Q000032:analysis* / Q000302:isolation & purification; D010860:Pigments, Biological / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis / Q000302:isolation & purification; D015203:Reproducibility of Results; D045470:Rubia; D032123:Santalum / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate; D035501:Uncertainty
chemical_list: D001391:Azo Compounds; D001578:Benzopyrans; D004396:Coloring Agents; D010860:Pigments, Biological; D010936:Plant Extracts; C438508:madder color; C009765:lac dye; D012967:Sodium Dodecyl Sulfate; C060327:dracorhodin; D002329:Carmine