Here is a link to a wiki page with useful information about the facility, sample submission, etc.
https://wikis.utexas.edu/display/GSAF/Home+Page.
You will need to have a UT EID (electronic ID)--mine is zg2788
Scott Hunicke-Smith (scotth@mail.utexas.edu) is the main guy in charge. You might e-mail him to let him know you have samples you want to submit so that they know who you are.