TLC of natural resins

Arlen Heginbotham <rothbotham [at] ids__net> writes

>I'd like to try to use thin layer chromatography to do some
>identification of natural resin varnish layers from a painted
>English chair ca.1800. I was wondering if anyone had a solvent
>system worked out which gives good separations on a given type of
>TLC plate.

For a first pass check out "Thin-Layer Chromatography for Binding
Media Analysis" by Mary Striegel and Jo Hill, Getty Conservation
Institute, Scientific Tools for Conservation, 1996. It's written
cookbook style and will walk you step by step through the method.
They give one solvent system for each class of materials
covered--resins, waxes, proteins, and carbohydrates. This will give
you something to start from, even if you end up fine-tuning the
method for your specific question.

If you think your samples may contain organic or resinous colorants,
and are willing to try 2-dimensional chromatography, see if you can
contact Scott Nolley about his methods (he gave an interesting talk
on this at AIC in 1996, examining tinted furniture varnishes).

According to the AIC directory Scott can be reached at the Colonial
Williamsburg Foundation, 757-565-8956,  snolley [at] cwf__org

Cindy Connelly Ryan
Library of Congress
Preservation Research and Testing Division
Washington, DC
202-707-3891

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                  Conservation DistList Instance 12:71
                 Distributed: Wednesday, March 3, 1999
                       Message Id: cdl-12-71-001
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