Description
The search for the chemical signature of death has focused over the past decade on desorption VOC methods of detection. Our group has been working on a method to detect the less easily detected but biogenically important polyamines that are well known to be part of the decomposition process – putrescine and cadaverine. Putrescine (PUT) and cadaverine (CAD) are known for their malodorous properties and may be important components that human remains detection (HRD) canines detect. To date, there are no published studies that have reported detecting these compounds in any of the forensic research of cadaver decomposition. As polyamines are volatile compounds known to readily absorb on polar surfaces, such as silica, they could be retained in soil for an indeterminate time and be an important factor in the chemical signature that is being detected by the HRD canines. The objective of this project was to determine if small biogenic amines can be detected from soil samples. First the amines were separated from soils as conjugate acids, basified, and extracted into a nonaqueous solvent. Fluorinated amide derivatives of PUT, CAD and other test amines were made and subsequently analyzed by negative ion chemical ionization (NICI) gas chromatography-mass spectrometry (GC-MS). Percent recoveries of the derivatives from sand ranged from 12-69%, and the detection limits were 0.05 ng to 0.20 ng for 1 gram sand samples. Percent recoveries from the same extraction procedures on four mixed soil samples ranged from 0.1 to 32% and experiments to improve recoveries were not successful. Mass spectra of the compounds were also evaluated by electron impact (EI) and positive chemical ionization (PCI), and NICI was found to be the superior method for detection. Difficulties remain in optimizing the extraction process, but the data reveals some interesting fragmentation patterns as well as presenting many questions left to be answered.
