دانلود کتاب Origin Identification of Pepper Spray and Tear Gas By Multivariate Data Analysis of Chemical Attribution Signatures

Abstract
Riot control agents, such as pepper spray and tear gas can be misused antagonistically and for criminal purposes. The legality of personal possession of pepper spray and tear gas varies between countries, and in Sweden, it is illegal to carry them in public. Pepper sprays and tear gases are commercially available and can be acquired from several web shops. In addition, there are several web pages and YouTube videos describing how to make homemade pepper spray by extraction of chilies. In this study, the aim was to examine if the identity and origin of analysed homemade pepper spray and commercial pepper spray and tear gas could be determined, based on chemical attribution signatures. Thirteen different chili types were acquired from six different distributors and 27 self-defence canisters of pepper spray and tear gas were acquired from two different distributors. Extracts of chilies and commercial pepper sprays and tear gases were analysed by GC-MS. By application of OPLS-DA, it was possible to differentiate between species, chili type and distributor/origin of the chilies. Furthermore, it was possible to differentiate between producer, label and batch number of the commercial pepper sprays and tear gases. The generated models were validated by application of an external test set consisting of chili acquired and extracted at a later instance, and by application of samples of seized commercial pepper spray and tear gas. In addition, residues of homemade pepper spray and commercial pepper spray and tear gas on surfaces were sampled up to six days after application, and their identity and origin were predicted. The models displayed high predictability, which enables them to be used for prediction of identity and origin of seized homemade and commercial pepper spray and tear gas. However, additional commercial pepper sprays and tear gases should be analysed in future and added to the models, in order to cover a wider range of producers and labels.