With National Science Foundation support, Dr. Mattanjah de Vries and Dr. Stuart Tyson-Smith and their graduate students will develop a technique for organic tracer molecule analysis for archaeometry. Their novel approach is based on a specialized form of laser mass spectrometry or LMS. In the vast arsenal of powerful analytical chemical techniques that are routinely used in archaeometry, the majority is particularly suited to elemental analysis. On the other hand, analysis of organic compounds in archeological samples is more challenging, generally requiring combinations of techniques and often yielding less specific identifications. The LMS technique will address these problems by combining the selectivity of resonant laser spectroscopy with the sensitivity of mass spectrometry. As a result LMS is simultaneously highly specific and sensitive.
The ability to detect and identify organic compounds in archeological samples is highly desirable because many types of samples can be uniquely characterized based on their organic molecular composition. Examples include food residues in pottery, affording a glimpse into what people ate or drank, resins, revealing materials used for incense, or dyes from which we can learn details on ancient coloring and manufacturing techniques as well as sources of materials and their trade routes. This project is interdisciplinary in nature, as the group of Dr. de Vries in the Department of Chemistry and biochemistry at UCSB is teaming up with the group of Dr. Tyson-Smith in the Department of Anthropology at the same university. The primary goals in this pilot study are to optimize the technique, to develop a catalogue of tracer compounds for archaeometric use, and to work with researchers in the field to facilitate further practical development of applications of the technique.
The unique combination of state of the art physical chemistry techniques with topics related to anthropology and archaeology is particularly suitable for educational projects. In addition to training graduate and postgraduate students, the research will involve undergraduate students as well as high school students, in the framework of UCSB sponsored outreach programs to minority students and high schools. In an additional collaboration students will participate from Jackson State University, a historically black college. Material from this research will also be shared with the Bay Area Museum-School Online Science Learning Collaboratory Pilot Project. In a broader sense, the ability to characterize ancient materials that were previously inaccessible to such analysis will open new windows to insights in our history and culture.
Intellectual merit In the vast arsenal of powerful analytical chemical techniques that are routinely used in archaeometry, the majority is particularly suited to elemental analysis. On the other hand, analysis of organic compounds in archeological samples is more challenging, generally requiring combinations of techniques and often yielding less specific identifications. This collaborative project at the University of California Santa Barbara, of the research groups of Prof. de Vries in the Department of Chemistry and Biochemistry and Prof Tyson-Smith in the Department of Anthropology, has developed a new technique to address these challenges. The approach employs a specialized form of laser mass spectrometry or LMS. This technique combines the selectivity of resonant laser spectroscopy with the sensitivity of mass spectrometry and is therefore simultaneously highly specific and sensitive. A further advantage is the capability to sample directly from artifacts, using laser pulses, without sample preparation. The project has also developed a new technique to obtain samples from areas of artifacts smaller than a micron (about a hundred times smaller than the diameter of a human hair). This technique employs an atomic force microscope to vaporize miniscule amounts of material, which is collected on a special substrate for subsequent analysis by the LMS technique. The team has demonstrated the capabilities of the LMS approach in an analysis of food residues in Mayan pottery. The results distinguished between different types of stimulant drinks, all containing caffeine but originating from different plants. The measurements show that some pottery contained cacao residues, while other types of pottery contained a more tea-like substance. The difference between the chemical signatures of these beverages is very subtle and the work showcases the strong combination of sensitivity and selectivity of the instrumentation. Broader impact The subject matter of this project is particularly suitable for educational projects. In addition to training undergraduate, graduate and postgraduate students with the research, it also providing research internships for undergraduate students as well as for high school students, in the framework of UCSB sponsored outreach programs to minority students and high schools: the Academic Research Consortium program and Research mentorship program, respectively. The unique combination of state of the art physical chemistry techniques with topics related to anthropology and archaeology has turned out to appeal very much to these younger students. The three seniors among the undergraduates will now continue in graduate school. One of these was a California Alliance for Minority Participation student, the first in her family to attend college at all. On a broader level, this work contributes to our understanding of culturally and anthropologically important aspect of the past
