Evaluation of Principal Components Analysis with High-Performance Liquid Chromatographhy and Photodiode Array Detection for the Forensic Differentiation of Ballpoint Pen Inks
- American Society for Testing & Materials
- Publication Type:
- Journal Article
- Journal of Forensic Sciences, 2001, 46 (4), pp. 878 - 883
- Issue Date:
Inks from seven black and eight blue ballpoint pens were separated by a high-performance liquid chromatography (HPLC) method utilizing a photodiode array detection (PDA). A classifier flowchart was designed for the chromatographic data based on the presence or absence of certain peaks at different wave-lengths to qualitatively discriminate between the inks. The same data were quantitatively classified by principal components analysis (PCA) to estimate the separation between a pair of classes of ink samples. It was found that the black ballpoint pen inks were discriminated satisfactorily utilizing two-dimensional data of the peak areas and retention times at the optimum wavelengths. The blue pens were discriminated by analyzing the chromatographic data at four different wavelengths simultaneously with a cross-validated PCA. The results of this study indicated that HPLC-PDA coupled with chemometrics could make a powerful discriminating tool for the forensic chemist, especially when analyzing extensive and/or complex data.
Please use this identifier to cite or link to this item: