Tuesday, September 21, 2010

Chemistry Seminar

Chemistry Seminar - Thursday, September 23 in RNS 390 Refreshments at 3:00 p.m. followed by the seminar at 3:15.

Forensic Characterization and Comparison of Nail Polish Removers in
Liquid Samples and Fire Debris

Nick Parker, Minnesota Bureau of Criminal Apprehension

St. Olaf College, Class of 2011

Nail polish removers contain flammable substances like acetone, and can be used to commit both arson and assault. It was the goal of this study to determine whether nail polish removers could be identified as such and/or differentiated among brands and varieties. Liquid samples of 61 nail polish removers were analyzed with gas chromatography-mass spectrometry to determine the content of each product, and a classification scheme was devised to maximally differentiate the nail polish removers on the basis of both brand and variety. A sample of 13 of these products were then used to accelerate fires, and the debris was analyzed by passive diffusion adsorption and GC/MS. Results showed that many but not all nail polish removers are differentiable, but future research is needed to make this type of analysis practical in working crime laboratories.

Making Sense of the Ribosome

Steven Braun
St. Olaf College, Class of 2011
Chemistry, Asian Studies (Japan Studies)

As the center of protein synthesis, the ribosome is one of the most essential components of the cell. Due to its great structural complexity, a great amount of research has been done to characterize local motifs, especially since the publication of the first full atomic resolution structure of the H. marismortui ribosomal complex in 2000. Even so, much of ribosomal structure is difficult to understand at first glance. This summer, I worked with Bob Hanson to investigate new methods of structural characterization and visualizations of the ribosome. The results of our work suggest that in order to truly make some sense of the ribosome, its beauty must be appreciated more significantly at the global level rather than the local level.

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