With this award from the Major Research Instrumentation (MRI) Program, Dr. Richard Newman from the Museum of Fine Arts and colleague Richard Laursen (Boston University) will acquire a capillary liquid chromatograph (LC) interfaced with an ion trap-mass spectrometer. The award will enhance research training and education at all levels, especially in areas such as analyses of natural and synthetic dyestuffs used in cultural artifacts (including textiles, easel and wall paintings, and polychromed sculpture). The objectives of this project are to gain insights into the compounds that are found in the raw (plant) source material; to enable comparisons between these compounds and those actually present on test samples that have been dyed or colored with the natural materials using a variety of extraction and dyeing procedures; as well as to provide information to identify the dyestuffs on deteriorated artifacts in which original dye components may have been significantly altered.
Mass spectrometers (MS) are used to identify the chemical composition of a sample by measuring the mass of the molecular constituents in the sample after they are ionized and detected. This instrument couples a capillary liquid chromatography system with the mass analysis ability. The liquid chromatograph separates minute volumes of mixtures of compounds extracted from the art pieces into its molecular components. These components then flow into a mass spectrometer where they are ionized and their masses determined. The instrumentation will be used not only for research that will help preserve art but also in laboratory courses at nearby Simmons College.
Of the several analytical techniques by which natural dyes used in cultural artifacts can be identified, liquid chromatography/diode array detector/mass spectrometry (LC/DAD/MS) currently provides the most comprehensive and detailed information. It is a technique that requires samples, and thus can only be applied to objects from which samples of sufficient size can be taken. Textiles are the major category of artifacts in which dyes are prominently utilized, and samples can generally be readily taken from such objects. Dyes also were prepared as lake pigments, utilized by painters, and LC/DAD/MS is sensitive enough to enable identifications of the dyes in very small paint samples to be determined. Other applications include dyed wood veneer on furniture. LC/DAD/MS is currently available in only three American museum science labs in addition to the Museum of Fine Arts, Boston (MFA), and given the importance of this analytical technique in the field of dyestuff research, we have collaborated and will continue to collaborate with conservators, scientists and curators from other institutions in studies of cultural artifacts that contain dyes. LC/DAD/MS is currently utilized by dyestuff researchers around the world, and results of such research are typically disseminated through specialist publications, conference proceedings, and occasional museum catalogs. As part of our grant, we have developed a LC/DAD/MS database within the Conservation & Art Materials Encyclopedia Online (CAMEO), an internationally-recognized free web resource available through the MFA website (cameo.mfa.org). The intent of this database is to serve as a clearinghouse for LC/DAD/MS analyses of samples from cultural artifacts and reference materials. It is only just beginning to be populated, but in the future all researchers will be able to submit data for inclusion. The database will eventually serve as a resource through which anyone interested in historic dyes can find occurrences of specific natural dyes, and through which researchers actively engaged in dye analysis can quickly compare results carried out by different sample preparation methods and with different instrumental setups. Extensive analyses carried out over the past ten years by Richard Laursen and collaborators at Boston University are in the process of being prepared for inclusion in the database. In 2008, the MFA purchased the Uemura Dye Archive, a set of over 700 dyed textile samples prepared from well-documented natural dye sources that cover the full range of historically important dyes used in traditional Japanese textiles. Photographs of each page of the archive, with English translation of all of the Japanese text, is currently available in CAMEO, and we are the beginning stages of LC/DAD/MS analyses of samples from the archive, results of which will be eventually entered in the CAMEO dyestuff database. Data from many of these reference samples will be an invaluable, unique resource for other researchers. A number of the materials included in the Archive have been little studied to date. A final focus of our ongoing work with the MFA’s LC/DAD/MS equipment is an exploration of how best to prepare various kinds of dye-containing samples for analysis and how to acquire and process data so as to fully exploit the capabilities of our instrument. As we build our expertise, we will be better able to offer expert advice and services to collaborators from other institutions in the future. In addition to our primary research on historic dyestuffs, we will make the insrument available to students carrying out senior research projects at Simmons College. LC/MS is not available at the college, and the ability to incorporate this analytical technique in some projects will be invaluable as a part of the undergaduate educational program at the college.
