In concomitance of the SEAHA Conference, SEAHA will open the door of the Heritage Science Laboratory where SEAHA students will show their experiments. There are programme two tours per day: between 17:17-18 and between 18-18:15.
Demonstration of VOC analysis of plastic objects via SPME by Mark Kearney
There are few options to monitor the health of plastic objects when either on display or in storage within museum environments. Solid phase microextraction gas chromatography mass spectrometry offers both a non-invasive and non-destructive method to examine the volatile organic compounds (VOC) emitted from plastic objects as they age and decay. Few institutions have the capability to carry out SPME analysis, however, UCL is one of the few with a wealth of institutional knowledge on the topic.
My proposed demonstration would show off this institutional knowledge to the participants of this year’s SEAHA conference. My 30 minute demo would focus on the practical issues surrounding the capture of VOCs from small objects as well as a examples of the results.
I will begin the demo with a short talk on the types of polymers that we have had success with. I will then cover our method for analysing small objects in a lab setting, covering bag choice, emission time and absorption time. I will also demonstrate how to expose the SPME fibre to the object. Finally, I will walk the group through my workflow on how to pick out VOCs and compare datasets to one another. I will also speak about some of the more common VOCs found when analysing plastic objects, especially when looking at cellulose acetate.
- Paper analysis techniques by Natalie Brown and Yujia Luo
Paper is a relatively stable organic material however, the main structural component, cellulose can undergo a series of degradation processes; ranging from thermolysis, light induced degradation, depolymerisation, acid hydrolysis and oxidation. This demonstration will focus on analytical and spectroscopic techniques used by researchers at the Institute for Sustainable Heritage to understand the effect of these processes on historic paper. Participants will be given detailed demonstrations of pH analysis methods, viscometry (used to measure degree of polyermisation), micro-chemical spot tests used to detect lignin and starch and colourimetry. We will discuss the experimental methodology, the benefits and drawbacks of these techniques, error and reproducibility, and how different paper characteristics; such as fibre composition, inhomogeneity and sizing could affect the analysis.
The participants will also be introduced to near-infrared spectroscopy (NIR) and chemometrics, an analysis method that can be used as a non-destructive alternative to analytical testing. We discuss the theoretical principles of this method as well as how to build chemometric models using spectroscopic data.
- Steps for the identification and quantification of airborne pollutants: passive sampling and analysis using Gas Chromatography-Mass Spectrometry (GC-MS) by Chryssa Thoua
As part of the laboratory demonstration participants will have the opportunity to look at the set up for indoor air sampling of volatile organic compounds (VOCs) using sorbent tubes. We will also have a look at the operation of instruments used to analyse the samples collected: these are Gas Chromatographer coupled with Mass Spectrometer, and linked to the Automated Thermal Desorber. We will review output from the instrument used to find out which compounds are present in indoor air and at what quantities