Characterization and differentiation of ballpoint pen ink strokes on paper using orbitrap mass spectrometry and multivariate statistic

• Autor(a) principal: Carvalho, Carina Maria Bello de
• Data de Publicação: 2018
• Outros Autores: Ortiz, Rafael Scorsatto, Reis, Monique dos, Zamboni, Amanda, Limberger, Renata Pereira, Ferrão, Marco Flôres, Vaz, Boniek Gontijo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/186267
• topic: Caneta esferográfica; Espectrometria de massa; Estatística multivariada; Análise forense; Ballpoint pen ink; Mass spectrometry; Orbitrap; Multivariate statistic; Forensic analysis; Documentoscopy

In criminal expertise routine, the expert is confronted by the challenge of detecting fraud in several important documents. One kind of forgery is the change of a document date of emission by one type of fraud is the adulteration of the date of emission of a document through the erasure and addition of another date with ballpoint pen of color similar to original. The forgery can be detected by characterization of colorant substances of each ink formulation. This could be done by using Orbitrap mass spectrometry. This study performed analysis in ESI-Orbitrap mass spectrometer to obtain the colorants and additives pattern of each brand of blue and black ballpoint pen tested, and after differentiated the pens by multivariate statistic (PCA and HCA). The analysis of ballpoint pen samples in a Q-Exactive® Orbitrap mass analyser was able to differentiate the samples, even for inks of very similar color, and the method proved to be very sensitive. The exact mass spectra were submitted to multivariate statistical analysis and the Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) was able to characterize the variables that were responsible for the variation and similarity of the samples. The HCA and PCA were able to group pens from the same brand and also to approximate pens of different brands but similar formulations. At the same time, multivariate analysis could identify pens that were very dissimilar from the others.