NCJ Number
229265
Journal
Journal of Forensic Sciences Volume: 54 Issue: 6 Dated: November 2009 Pages: 1270-1277
Date Published
November 2009
Length
8 pages
Annotation
Since human scent evidence collected from objects at a crime scene is used for scent discrimination with specially trained canines, this study identified the optimal medium for storing human scent evidence by comparing the performance of scent-evidence containers of glass, polyethylene, and aluminized pouches.
Abstract
Glass was determined to be the optimal type of storage container for human-scent samples. Compared with the other container materials, glass had the least overall compounds transferred to the cotton scent-sample materials, as well as fewer compounds previously reported to be present in human scent. Glass storage materials are most often used by human-scent canine units across Europe. When analytically clean cotton materials were stored inside various polymer and aluminized materials, a significant amount of compounds were imparted to the cotton material, including compounds previously found to be present in human scent. The Dukal brand gauze sorbent materials for scent evidence gave the highest similarity values. The results show that scent samples should not be exposed to excessive amounts of UVA/UVB light, since this will result in the detection of a greater number of methyl esters and aldehydes in the headspace of the sample, which may alter the human-scent profile. The study collected had odor samples on three different sorbent materials, sealed in glass vials, and subjected to different storage environments that included room temperature, -80 degrees C, dark storage, and UVA/UVB light exposure over a 7-week period. Volatile organic compounds in the headspace of the samples were extracted and identified with solid-phase micro-extraction-gas chromatography/mass spectrometry. Three-dimensional covariance mapping was used to compare the performance of the evidence containers. 5 tables, 4 figures, and 22 references