NSF Graduate Fellow
Modern Methods to Unlock Ancient Chemical Clues: The Extraction of Fat Residue from Charcoal to Determine Partition Coefficients
Dr. Jeffrey J. Rosentreter
University Department and/or Lab:
I hope to further my education in chemistry by working towards obtaining a Ph.D in medicinal chemistry.
Description of Research:
What constituted the diet of ancient societies continues to be an important question many archaeologists have sought to answer. A key to this exhaustive investigation may lie in the debris that has been left behind in the fire pits and ovens used to prepare their food. The fat residues that may still be preserved in the charcoal contain vital information, namely fatty acid residue ratios, that should improve our understanding of the precise character of food prepared. Our research activities have developed and optimized a method for the carbonization of wood into charcoal for the laboratory setting. Here use of a temperature programmed tube furnace facilitates the creation of precise artificial samples that contain minute quantities of fat residue. A method has also been developed to quantitatively load fats (triglycerides) onto charcoal so that further extraction can be performed. Kinetic experiments were completed to quantify the required steady state extraction times. Using the above-mentioned techniques, partition coefficients have been found between solid/solvent matrices containing various charcoal types in combination with a number of different organic solvents all of which vary in their dielectric constants. These distribution coefficients have been used to identify suitable solvent medium in which fat-containing charcoal can be placed for the best possible extraction. All final analysis were performed by first extracting the fat residue from the charcoal, esterifying the triglyceride into fatty acid methyl esters (FAMEs) by following the base-catalyzed esterification mechanism, and ultimately performing quantitative examination by using GC/MS methods.
One example of how you integrate your research into your GK-12 experience:
My research involves the study of triglycerides, which are major components of many different types of food. Fatty acid ratio profiles provide characteristic information as to what determines the identity of many of these food groups. The various nutrients found in food provide the necessary nourishment that the human body needs in order to maintain survival. Our hope, through this partnership, is to make the subject of Chemistry more relevant to Anatomy and Physiology students through a series of laboratory investigations involving nutritional chemistry.