TY  - JOUR
PY  - 2017//
TI  - Using cluster analysis and ICP-MS to identifygroups of ecstasy tablets in Sao Paulo State, Brazil
JO  - Journal of forensic sciences
A1  - Maione, Camila
A1  - de Oliveira Souza, Vanessa Cristina
A1  - Togni, Loraine Rezende
A1  - da Costa, Jose Luiz
A1  - Campiglia, Andres Dobal
A1  - Barbosa, Fernando
A1  - Barbosa, Rommel Melgaço
SP  - 1479
EP  - 1486
VL  - 62
IS  - 6
N2  - The variations found in the elemental composition in ecstasy samples result in spectral profiles with useful information for data analysis, and cluster analysis of these profiles can help uncover different categories of the drug. We provide a cluster analysis of ecstasy tablets based on their elemental composition. Twenty-five elements were determined by ICP-MS in tablets apprehended by Sao Paulo's State Police, Brazil. We employ the K-means clustering algorithm along with C4.5 decision tree to help us interpret the clustering results. We found a better number of two clusters within the data, which can refer to the approximated number of sources of the drug which supply the cities of seizures. The C4.5 model was capable of differentiating the ecstasy samples from the two clusters with high prediction accuracy using the leave-one-out cross-validation. The model used only Nd, Ni, and Pb concentration values in the classification of the samples.<br><br>© 2017 American Academy of Forensic Sciences.<p />  <p>Language: en</p>
LA  - en
SN  - 0022-1198
UR  - http://dx.doi.org/10.1111/1556-4029.13448
ID  - ref1
ER  -