NCJ Number
215141
Journal
Journal of Forensic Sciences Volume: 51 Issue: 4 Dated: July 2006 Pages: 780-789
Date Published
July 2006
Length
10 pages
Annotation
This evaluation of the Scent Transfer Unit (STU-100)--which is a portable vacuum that uses airflow through a sterile gauze pad to capture a volatiles profile over evidentiary items for subsequent presentation to a trained dog--determined its ability to trap and release organic compounds at ambient temperature under controlled laboratory conditions.
Abstract
For each of the two analytical methodologies--gas chromatography-mass spectrometry (GC-MS) and thermal desorption with atmospheric chemical ionization mass spectrometry (TD/APCI-MS)--the STU-100 demonstrated effective loading and subsequent release of analytes with high volatility in both liquid and gaseous forms. In addition, the multivariate analysis produced information on the volatile and semivolatile organic compound patterns and clustering that could be differentiated in factor space. The mass spectral patterns that resulted after spiking the volatiles capture pads with various perfumes could be distinguished by the TD/APCI-MS approach both visually and chemometrically. By displaying the data in factor space, clustering of the patterns is evident and provides further indication that the pads used in the STU-100 can trap (adsorb) and release (desorb) chemical mixtures. Future work will involve the use of test mixtures that are representative of the human odor components that have been found in experiments. This will provide a better understanding of the nature of dog scent detection and determine variation of airflow volumes for more efficient volatiles adsorption. The description of the experimental methods addresses the matrix spike mix, volatiles gas loading to the STU-100 pad, and the TD/APCI-MS procedures. 6 tables, 10 figures, and 22 references