1. Authors’ Information, Intended Audience & Abstract

Authors’ Information

Patricia E. Gonzales, Pontificia Universidad Católica del Perú; pgonzales@pucp.pe

Betty C. Galarreta, Pontificia Universidad Católica del Perú; bgalarreta@pucp.pe

Publishing Information

Published March 2024

Intended audience:  Undergraduate or graduate

This module can be used for early career conservators, chemists or any other students or professionals in areas related to cultural heritage, who wish to develop their research skills to solve specific questions using techniques available in the chemistry laboratory (e.g. X-ray fluorescence spectrometry (XRF), Raman spectroscopy, Fiber Optics Reflectance Spectroscopy (FORS), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD)) and study the historical and cultural information of the analyzed objects. The level of difficulty of this module can be modified based on the students’ background and the research topics and data selected for the projects.

Abstract

The Chemistry Section at the Pontificia Universidad Católica del Perú offers a variety of mandatory and elective courses that are open to a broader audience, both as part of our regular curricula and, recently, as open courses. The applications of chemistry in art and archaeology constitute an excellent opportunity to promote active learning in an interdisciplinary context, and it is an attractive topic for non-Chemistry majors. With this idea in mind, a course was designed focused on the interdisciplinary analysis of cultural heritage objects, with emphasis on their chemical components and on the techniques used for their study.

In order to make it easier for students to understand instrumental analysis in this context, a mini research project activity was designed. The students, organized in groups, would select an object that was of interest to them, propose a question and try to solve it using techniques available to them in the laboratory (e.g., XRF, Raman, FORS, FTIR, XRD). The COVID-19 pandemic presented a serious challenge to the course design, as in-person activities were not allowed; however, a decision was made to keep as much as possible from the original design of this activity. To this end, papers that had very detailed instrumental analysis information on several and very diverse objects were selected. Students were given an overview of the problem that needed to be solved in each case and they chose the topic or object that interested them the most. Once they had selected their project, data was provided to each group gradually, over the course of three class sessions, and in response to the sequence of analyses they proposed for their study. The students were asked to refrain from actively looking for the paper or papers where the information had come from, which they did honor. Each week they had to present their findings to their classmates, professors, and guest specialists, and justify the need for the next analysis step. At the end of the term, an oral presentation was held, with the results of their investigations. This presentation was open to the public.

Working in this manner, students gained a better idea of the questions that can be answered through chemistry and instrumental analysis, as well as the limitations one can encounter both due to the techniques and the objects. Even though the original plan had been to use techniques that were accessible to the students on campus, the approach forced by the COVID-19 pandemic worked very well and can be used for cases in which there is limited accessibility to instrumentation. Moreover, during this time in which courses have been held mostly online, the authors have discovered the benefits of having spaces to discuss experimental design and results, separate from the actual laboratory time, which tends to be busy and limited by time constraints. This has allowed for a deeper engagement and thought process from the students, and they have truly valued this approach. Based on this experience, the authors believe this module can be used as a course activity in its own right, apart from the hands-on activities that will be resumed once we can hold this course fully in person again.

2. Introduction

Hypothesis

By working on an interdisciplinary research project, students gain a better sense of the questions in cultural heritage that can be answered through chemistry and instrumental analysis, as well as the limitations one can encounter both due to the techniques and the objects.

Simulating a research project using detailed information on the instrumental analysis of an object from the literature (or previously collected instrumental analysis data available to the instructor) is a valuable activity that develops the necessary skills in the students.  This is also a good alternative when there is limited accessibility to specialized equipment.

Threshold Concept

Application of analytical chemistry techniques to cultural heritage materials (XRF, Raman, FORS, FTIR, XRD) through interdisciplinary research.

Major Goals and Outcomes

Students will:

• Apply the chemical techniques used in the study of cultural heritage objects to a specific research problem.
• Critically assess the chemical data obtained or provided, determine the limitations one can encounter both due to the techniques and the objects; and correlate these results with the information provided by other disciplines to show the importance of interdisciplinary projects.
• Demonstrate the ability to organize ideas around a topic and incorporate relevant content and evidence to request more analysis and information, to prepare an informative presentation based on the data provided and other references.

3. References

This is a list of the papers used as source of information for the projects:

Carvalho, Isamara, Conceição Casanova, Rita Araújo, and Ana Lemos. 2018. “Colour identification, degradation processes and findings in a fifteenth-century Book of Hours: the case study of Cofre n. º 31 from Mafra National Palace.” Heritage Science 6 (9): 1-17.

Centeno, Silvia A., Veronica I. Williams, Nicole C. Little, and Robert J. Speakman. 2012. “Characterization of surface decorations in Prehispanic archaeological ceramics by Raman spectroscopy, FTIR, XRD and XRF.” Vibrational Spectroscopy 58: 119– 124.

Delbey, Thomas, Jakob Povl Holck, Bjarke Jørgensen, Alexandra Alvis, Vanessa Haight Smith, Gwénaëlle M. Kavich, Kimberly A. Harmon, Bertil Fabricius Dorch, and Kaare Lund Rasmussen. 2019. “Poisonous books: analyses of four sixteenth and seventeenth century book bindings covered with arsenic rich green paint.” Heritage Science 7, no. 91.

Lera, Thomas M., Jennifer A. Giaccai, and Nicole Little. 2013. “A scientific analysis of the First Issues of Chile 1853–1862, London printing.” in Proceedings of the First International Symposium on Analytical Methods in Philately, edited by Thomas M. Lera, John H. Barwis, and David L. Herendeen, 19–33. Washington: Smithsonian Institution Scholarly Press.

Martin, R. R., S. J. Naftel, A. J. Nelson, M. Edwards, H. Mithoowani and J. Stakiwc. 2010. “Synchrotron radiation analysis of possible correlations between metal status in human cementum and periodontal disease.” Journal of Synchrotron Radiation 17, no. 2 (Mar) 263–267.

Morillas, Héctor, Maite Maguregui, José Bastante, Gladys Huallparimachi, Iker Marcaida, Cristina García-Florentino, Fernando Astete, and Juan Manuel Madariaga. 2018. “Characterization of the Inkaterra rock shelter paintings exposed to tropical climate (Machupicchu, Peru).” Microchemical Journal 137: 422-428.

Pozzi, Federica, Elena Basso, and Monica Katz. 2020. “In search of Humboldt’s colors: materials and techniques of a 17th-century lacquered gourd from Colombia.” Heritage Science 8: 101-116.

Tomasini, Eugenia, Diana Castellanos Rodríguez, Blanca A. Gómez, Dalva L.A. de Faria, Carlos Rúa Landa, Gabriela Siracusano, and Marta S. Maier. 2016. “A multi-analytical investigation of the materials and painting technique of a wall painting from the church of Copacabana de Andamarca (Bolivia).” Microchemical Journal 128: 172-180.

4. Key Image and Power Points Presentations

Key Image

Power Point Presentations

Libros venenosos [pdf]

Poisonous Books [pdf]

Analisis de estampillas [pdf]

Stamp Analysis [pdf]

5. Course Plan

The following describes one activity was that was carried out as part of the school term (16 weeks):

Week 1

The activity was explained to the students, and they were asked to provide a list of their topics of interest.

Weeks 2 to 7

The professors gathered several papers trying to cover all topics listed by the students and prepared very short documents with introductions on each potential project.

Week 8

The projects were introduced orally during the class session and the brief documents were also uploaded to a shared Google Drive folder. The students selected their preferred project (they formed groups of 3-4 students, based on common interests) during the course of the week and started gathering information on their chosen project.

Week 12

The students did a first oral presentation on their topic and requested the first set of analysis to address the question or questions that needed to be solved.  The need for these analyses was discussed in the class session, with the participation of all the students, the professors, and the guest experts.  During the week, the students were provided with the data from the requested analyses, which they in turn processed with their team.

Week 13

The students did their second oral presentation, incorporating the newly processed data and once again requested further analyses. They were provided with the information, which they once again processed with their team.

Week 14

The students did their third oral presentation, incorporating the newly processed data and were given the option to request further analyses if they considered them necessary.  They were also given the chance to request office hours with the professors or experts if they needed further assistance.

Week 15

The students did a final oral presentation on their findings, open to the public.

Included are examples of the way the information was presented to the students over the course of the activity (in the original language (Spanish) and in an English version):

1. For the project on first issues of Chilean postage stamps
2. For the project on poisonous books

In the case of the second project, additional information (XRF and Raman data) was provided by Dr. Rosie Grayburn, Head of the Scientific Research and Analysis Laboratory (SRAL) at the Department of Conservation of the Winterthur Museum, Garden & Library. This information is part of the Winterthur Poison Book Project.

In some cases, the students would request analyses that were not reported in the papers that were used.  Instead of viewing this as an obstacle, it was an advantage: in those cases, the students were told that the instrument was not accessible (or was not functioning properly) or that the conservator/curator/owner of the piece did not allow sampling.  These are issues frequently encountered in real life scenarios, so working in this manner contributed to further make the experience relevant and also forced the students to be creative and look for alternatives for situations they considered less than ideal.

6. Methods for Student Engagement

On average, half of the students in this course were Chemistry majors. The other half was composed of Engineering students and conservators. At the beginning, the main challenge was that the non-Chemistry majors showed some concern because they felt that the concepts discussed throughout the course could be too complex for them to grasp. Students were reassured that this was not the case and that every student could get something out of the course and could also provide the rest of the group with valuable knowledge and experience.  Emphasis was put on the fact that the aim was not to turn every student into a conservation scientist with one course taught in one school term.  Instead, what was needed was to develop a common background and language so that, for instance, the conservator could better interact with the chemist in the course of an investigation.  By the end of the course, both instructors considered that, far from being the only ones facilitating information, they learned a great deal from the invited specialists, of course, but also from the students, who brought their own ideas and expertise to every session.

The group was very lucky to have guest specialists from different disciplines present throughout the entire course: two conservators who work with the instructors on several research projects (one based in Lima, and one based in Chile), an archaeologist who is also the director of the university’s archaeological museum, and an artist who is also an art handler at a museum in New York City. Having them in class made it possible to have a rich discussion in each session and it made it easier for the students to feel comfortable with asking questions, sharing their ideas and experiences. This type of dynamic promoted active learning in an interdisciplinary context. Students realized the analytical chemistry data needs to be correlated with the information provided by conservators and other professionals in areas related to cultural heritage to answer a particular research question on object or material under study. Based on the experience with this course, the authors highly recommend inviting specialists to participate in courses that are focused on cultural heritage, even if they can only participate in a few sessions.

Distance learning, forced by the Covid-19 pandemic, also made it possible to have specialists from other parts of the world virtually participating in the course, which the authors would also recommend, in order to showcase and promote the international research networks one often encounters when working with cultural heritage.

For the Chemistry majors, apart from further exploring instrumental analysis in a different context, the course provided them with an opportunity to really think about the analyses that need to be done in order to answer the proposed questions.  In general, because of their training, Chemistry majors tend to request multiple analyses on a sample and do it in duplicates or even triplicates.  Having to face a conservator telling them to limit themselves to a less than ideal microsample (or to non-destructive analysis) or an archaeologist questioning the need for a certain analysis was an eye opener for many of the students and it forced them to think outside of the box and take into account ethical aspects which are extremely important in cultural heritage research.