Espectroscopía vibracional e imágenes hiperespectrales aplicadas a la clasificación quimiométrica de residuos de disparo
Vibrational spectroscopy and hyperspectral images applied to the chemometric classification of gunshot residues.
| dc.contributor | Yáñez, Jorge | |
| dc.contributor | UNIVERSIDAD DE CONCEPCION | |
| dc.creator | Álvarez Jiménez, Ángela Lizeth | |
| dc.date | 2019-08-06T19:49:25Z | |
| dc.date | 2022-08-18T04:30:51Z | |
| dc.date | 2019-08-06T19:49:25Z | |
| dc.date | 2022-08-18T04:30:51Z | |
| dc.date | 2019 | |
| dc.date.accessioned | 2023-08-22T07:00:28Z | |
| dc.date.available | 2023-08-22T07:00:28Z | |
| dc.identifier | 21161209 | |
| dc.identifier | https://hdl.handle.net/10533/236406 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/8330218 | |
| dc.description | Crimes involving firearms and explosives have increased in recent decades globally, which effect on security sense of society. Currently, gunshot residues (GSR) detection is based on the determination of Pb, Ba and Sb by scanning electron microscopy with energy dispersive detector (SEM-EDX), without considering the organic components. The recognition of GSR based only in those three metals has some disadvantages such as the increasing use of lead-free ammunition, environmental or occupational sources of metals associated to GSR, induce uncertainty in their recognition. In this work it has been considered that the GSR organic analysis can provide complementary forensic information to the current method. Vibrational methods, such as photoacoustic (PAS), attenuated total reflectance Fourier transform infrared (ATR-FTIR), hyperspectral imaging and Raman spectroscopy, are highly selective and non-destructive analytical techniques able to provide organic GSR profile information. The chemical composition of GSR depends on the combination of several factors including type of weapon and ammunition (manufacturer, caliber), distance and angle of the shot, and environment conditions. The identification of the ammunition manufacturer used in firearms or explosives events can provide relevant information for forensic purposes. PAS, ATR-FTIR and Raman spectroscopic studies of GSR originating from firing ammunition produced by three different manufacturers (Fiocchi, Maxxtech and Remington). Differentiation of the manufacturers was achieved using the vibrational fingerprint of the GSR coupled with chemometric methods. GSR were collected using tape-lifting protocol from cloth targets, which simulate victim clothes. Principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA) were used to achieve an effective differentiation and classification (100%) of GSRs based on ammunition manufacturer. The results demonstrated the advantages of using the organic profile spectral for GSR identification and differentiation. The GSR detection on skin is an established practice in forensic laboratories. ATR-FTIR hyperspectral microscopy and Raman spectroscopy were applied to detect organic GSR on the shooter hands and to determinate of the weapon (caliber) used, respectively. GSR were acquired from discharge of different ammunition manufacturer and caliber (9 mm and .38”). Positive detection of OGSR was achieved by hyperspectral imaging ATR-FTIR. However, the determination of weapon and caliber from Raman spectra were not achieved due to the non-uniform GSR detection in the collected samples. | |
| dc.description | PFCHA-Becas | |
| dc.description | PFCHA-Becas | |
| dc.format | application/pdf | |
| dc.relation | instname: Conicyt | |
| dc.relation | reponame: Repositorio Digital RI2.0 | |
| dc.relation | info:eu-repo/grantAgreement//21161209 | |
| dc.relation | info:eu-repo/semantics/dataset/hdl.handle.net/10533/93488 | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.rights | http://creativecommons.org/publicdomain/zero/1.0/ | |
| dc.subject | Ciencias Naturales | |
| dc.subject | Ciencias Químicas | |
| dc.title | Espectroscopía vibracional e imágenes hiperespectrales aplicadas a la clasificación quimiométrica de residuos de disparo | |
| dc.title | Vibrational spectroscopy and hyperspectral images applied to the chemometric classification of gunshot residues. | |
| dc.type | Tesis Doctorado | |
| dc.type | info:eu-repo/semantics/doctoralThesis | |
| dc.type | info:eu-repo/semantics/publishedVersion | |
| dc.type | Tesis |