Analysis of natural red dyes (cochineal) in textiles of historical importance using HPLC and multivariate data analysis
| Autor: | João A. Lopes, Ana Serrano, M. Conceição Oliveira, Micaela M. Sousa, Jessica Hallett |
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| Rok vydání: | 2011 |
| Předmět: |
Cochineal
Insecta Textile Resolution (mass spectrometry) Carmine Biochemistry High-performance liquid chromatography Mass Spectrometry Analytical Chemistry History 17th Century Chromatography detector Animals Sample preparation Chromatography High Pressure Liquid History 15th Century Mathematics Principal Component Analysis Chromatography biology business.industry Textiles History 19th Century biology.organism_classification History 16th Century Multivariate Analysis Principal component analysis business Natural dye |
| Zdroj: | Analytical and Bioanalytical Chemistry. 401:735-743 |
| ISSN: | 1618-2650 1618-2642 |
| DOI: | 10.1007/s00216-011-5094-0 |
| Popis: | A new analytical approach based on high-performance liquid chromatography with diode array detector (HPLC-DAD) and multivariate data analysis was applied and assessed for analyzing the red dye extracted from cochineal insects, used in precious historical textiles. The most widely used method of analysis involves quantification of specific minor compounds (markers), using HPLC-DAD. However, variation in the cochineal markers concentration, use of aggressive dye extraction methods and poor resolution of HPLC chromatograms can compromise the identification of the precise insect species used in the textiles. In this study, a soft extraction method combined with a new dye recovery treatment was developed, capable of yielding HPLC chromatograms with good resolution, for the first time, for historical cochineal-dyed textiles. After principal components analysis (PCA) and mass spectrometry (MS), it was possible to identify the cochineal species used in these textiles, in contrast to the accepted method of analysis. In order to compare both methodologies, 7 cochineal species and 63 historical cochineal insect specimens were analyzed using the two approaches, and then compared with the results for 15 historical textiles in order to assess their applicability to real complex samples. The methodology developed here was shown to provide more accurate and consistent information than the traditional method. Almost all of the historical textiles were dyed with Porphyrophora sp. insects. These results emphasize the importance of adopting the proposed methodology for future research on cochineal (and related red dyes). Mild extraction methods and HPLC-DAD/MS(n) analysis yield distinctive profiles, which, in combination with a PCA reference database, are a powerful tool for identifying red insect dyes. |
| Databáze: | OpenAIRE |
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