Preparing brittle wood samples for SEM

Mahmoud Youssif Abd El-Wahab <conservator005 [at] yahoo__com> writes

>I will do some investigation of archaeological wood samples (dry
>condition) by the Scanning Electron Microscope, some of which are
>very brittle. The problem mainly is with the cross section. I am
>seeking your advice about the best method of preparation (embedding,
>etc.) to have good clear image.  NB I don't want the preparation
>method to have any impact on the anatomical characteristics of the
>sample.

If you do not want to embed the samples at first, use a conductive
substrate and examine them in a low-vacuum (LV) SEM. We have two
here that are workhorses for examining organic material without
coating or embedding. The LV-SEM uses a backscatter detector to
image samples in relation to either their elemental composition or
topography. I have examined many architectural wood samples this way
with excellent results-you can even perform EDS on layers. The other
option is to use a Field-Emission (FE) SEM at very low voltages
(<5kV).

Joe Swider
Senior Research Scientist
McCrone Associates, Inc.
Westmont, IL


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                  Conservation DistList Instance 27:4
                   Distributed: Tuesday, July 2, 2013
                        Message Id: cdl-27-4-001
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