Indiana University Purdue University Indianapolis

Dee Ann Turner

LD 302
(317) 274-6870

BS in Chemistry, IUPUI, 2008

Pursuing Ph.D. in Analytical Chemistry

Research Interests: 

My research involves monitoring, characterizing, and preventing microbial degradation of ignitable liquids in soil. In cases of suspected arson, an ignitable liquid is often used to start the fire. Ignitable liquids are classified according to chemical composition and boiling point range. Substrates such as soil and rotting wood have high organic matter content and therefore provide a rich medium for bacteria populations. These bacteria can also metabolize the components of various ignitable liquids such as gasoline. Metabolism is based on the chemical structure of the compounds. Normal alkanes, such as octane and decane, and lesser substituted aromatics, such as toluene and ethylbenzene are most susceptible to microbial degradation. Microbial degradation has been monitored over time for many ignitable liquids. Microbial degradation has also been characterized using Principal Components Analysis (PCA), which is a multivariate statistical technique that reduces the dimensions of a complex data set to 2 -3 dimensions so that trends in the data can be more readily realized. Preventing degradation in order to preserve ignitable liquid residues is the ultimate goal for this project. Suggested methods for preventing degradation such as refrigerating/freezing, autoclaving, or using UV radiation are not practical for use in forensic science. Fire debris samples often do not reach the laboratory for days or even weeks, leaving ample time for the bacteria to metabolize the ignitable liquid residue to point where it is no longer identifiable. A more practical approach is to apply a chemical agent to the fire debris samples upon collection, which will kill bacteria present, thereby preserving the ignitable liquid residue, but also does not interfere with sample analysis.