Dye Analysis

Dye Analysis by Chromatography

The Dye Analysis database includes analyses of reference dye materials and analyses of samples from cultural artifacts that have been carried out by liquid chromatography, generally coupled with diode array and mass spectrometer detectors (LC/DAD/MS). The database covers natural as well as synthetic dyes. Individual records generally include images of chromatograms from both detectors (absorbance at one or more wavelengths; total ion, base peak or extracted ion chromatograms). Images of UV/visible spectra from individual compounds are included. Mass spectra that only show the molecular ion are generally not included. Mass spectra containing useful information on fragmentation of the molecular ion are included, as are mass spectra from multistage mass spectrometry (MS/MS) if such a technique was utilized.

Each record features a table of specific compounds identified in a sample, which includes the common name of the compound, molecular weight (or major ion, if this is a fragment), and major UV/visible absorbance wavelengths. Many analyses include small, unidentified peaks, which usually will not be discussed in a record unless they are particularly pertinent to characterization. Original data sources (published or unpublished) are indicated, from which more detailed information on interpretation than can be included in the record may be available. Details of sample preparation, instrumentation and analytical conditions for each chromatogram are included.

Dye Analysis database subcategories

Records in the database are sorted into five subcategories within two main categories “Reference materials” (subcategories “Natural dyes” and “Synthetic dyes”) and “Cultural artifacts” (subcategories “Textiles,” “Paintings” and “Objects”).

Subcategory “Natural Dyes”

For the natural dyes, there is one record for each plant or insect source. The record includes information on the source, an image or images of the raw material, a brief history of the use of the dye and how the dyes compounds are typically extracted from the source. A given record typically includes multiple analyses carried out on different equipment under different operating conditions.

Subcategory “Synthetic dyes”

Synthetic dyes may consist of single compounds or mixtures of a few compounds. An individual record will cover a material with a single Colour Index number. The material may have been and still may be marketed under various names by different manufacturers, at least some of which will be noted in the record. An individual record may include analyses of samples from multiple manufacturers, as well as analyses carried out on different equipment and operating conditions.

Main category “Cultural artifacts” (with subcategories “Textiles,” “Paintings,” and “Objects”)

This category comprises records of analyses of dye-containing samples from cultural artifacts. A record generally shows results from one object, which will be identified by title, attribution, owner and owner’s identification information. If possible, an image of the cultural artifact is included. Artifacts are divided into the three subcategories textiles, paintings and objects. Within each record are be images of chromatograms and other data associated with the analysis of samples that contained dyes. The records will not discuss material aspects of a given work of art that are not directly to the dye-containing sample or samples. References to other analyses are given and can be consulted for this additional information.

How to use the Dye Analysis database

The full list of database records is below. Clicking on a subcategory above (or below) will generate a list of records for that subcategory. The search box in the upper right may be used to search for all records that contain a specific compound (for example, alizarin). A search on any word or phrase will show all records containing that word or exact phrase.

Credits

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