Statistical Discrimination of Blue Ballpoint Pen Inks by Infrared (IR) Spectroscopy
Keywords:Blue ballpoint pen inks, PCA, AHC, FTIR,
AbstractStatistical chemometric method was used in discriminating 24 blue ballpoint pen inks from six different brands (Pilot, Carera, Stabilo, Faber-Castle, G-soft and Papermate) available in Malaysian market. Discrimination method was developed based on the combination of infrared spectra (IR) and chemometric technique which comprise of principal component analysis (PCA) and Agglomerative Hierarchical Clustering (AHC). The chemometric software used was XLSTAT 2011. The spectral region 4000–400 cm-1 was used to ‘fingerprint’ each ink from the 24 samples. PCA was used to detect any outliers whereas AHC was used to separate the ballpoint pen inks into their own class. This study showed that acceptable statistical discrimination (70.92% correct classification of the ballpoint pen dataset) between these 24 samples. FTIR-PCA and FTIR-AHC were successfully discriminate three different brands which were Carera, Pilot and g-soft. While, the other three brands, Papermate, Fabercastle and Stabilo could not be discriminated perfectly. The results of this study indicate that Transmission FTIR Spectroscopy coupled with chemometrics is useful discriminating tool for forensic studies involving inks.
Williams, M.R., Moody, C., Arceneaux, L.A., Rinke , C., White, K., Sigman, M.E., (2009). Analysis of black writing ink by electrospray ionization mass spectrometry. Forensic Science International, 191, 97-103.
Thanasoulias, N.C., Parisis, N.A., Evmirids, Nicholaos P., (2003). Multivariate chemometrics for the forensic discrimination of blue ball-point pen inks based on their Vis Spectra.Forensic Science International, 138, 75-84.
Djozan, D., Baheri, T., Karimian, G., Shahidi, M., (2008). Application of the micro–FTIR spectroscopy, Raman spectroscopy and XRF method examination of inks. Forensic Science International, 158, 164-172.
Adam, C.D., Sheratt, S.L., Zholobenko, V.L., (2008). Classification and individualization of black ballpoint pen inks using principle component analysis of UV-vis absorption spectra. Forensic Science International,174, 16-25.
Dirwono, W., Park, J.S., Agustin-Camacho, M.R., Kim, J., Park, H-M., Lee, Y., Lee, K-B., (2010). Application of micro-attenuated total reflectance FTIR spectroscopy in the forensic study of questioned documents involving red seal inks. Forensic Science International, 199, 6-8.
Senvaitiene, J., Beganskiene and Kareiva, A., (2005). Spectroscopic evaluation and characterization of different historical writing inks. Vibrational Spectroscopy, 37, 61-67.
Gallidabino, M., Weyermann, C., Marquis, R., (2010). Differentiation of blue ballpoint pen inks by positive and negative mode LDI-MS. Forensic Science International, 6103,10 M. Hu, K. Kransz, J. Chen, G. X. Jun, J. Li, and H. Gelboin, Drug Metabolism and Disposition, 31 (2003), 924-931.
Kher, A., Mulholland, M., Green, E., Reedy, B., (2006). Forensic classification of ballpoint pen inks using high performance liquid chromatography and infrared spectroscopy with principal components analysis and linear discrimin ant analysis. Vibrational Spectroscopy, 40, 270–277.
Denman, J. A., Skinner, W.M., Kirkbride, K..P., Kempson, I.M. 2010. Organic and inorganic discrimination of ballpoint pen inks by ToF-SIMS and multivariate statistics. Applied Surface Sci. 256 :2155–2163.
Panero, F.S. and da Silva, H.E.B. 2008. Application of exploratory data analysis for the characterization of tubular wells of the North of Brazil. Microchemical Journal, 88, 194–200.