Chromatic analysis of blue ballpoint pen inks and related dyes

Abstract

Analysis of ballpoint pen inks on questioned documents is often required in the field of forensic analysis to identify the writing implement used in the commitment of a crime. In forensic work, it is thus necessary to identify the manufacturer of the pen or the specific ink product. In this article, a forensic analysis is documented for discrimination of a series of ballpoint pastes to identify the chromatic components used for blue ballpoint pen inks and thus to establish the writing instrument used in a questioned document. To achieve this, data of various adequate techniques have been corroborated: X‐ray fluorescence spectroscopy, ultraviolet–visible–near‐infrared spectrophotometry, in diffuse reflection and transmission modes, completed by trichromatic analyses, and thin layer chromatography. A protocol consisting of four steps has been proposed, in which various components provided by a database of reference dyes are removed, selected, and combined to assess the possible identity of an unknown pen ink paste among a set belonging to the same color pallet. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 169–177, 2015

How Much Can a Forensic Laboratory Do to Discriminate Questioned Ink Entries?

“…Based on the published literatures regarding the forensic analysis of blue ballpoint inks , an LC‐MS/MS method established by our laboratory for the analysis of four basic dyes that are most frequently used in blue ballpoint inks, that is, crystal violet (CV), Methyl violet (MV), basic blue 7 (BB7), and Victoria blue B (VB), was employed to distinguish the 18 ink samples. The tandem mass spectrometry parameters for the detection of these analytes were listed in Table .…”

“…Blue ballpoint ink entries are common samples in questioned document examination. Numerous methods have been developed to discriminate blue ballpoint inks, for example, UV‐visible spectroscopy , Raman spectroscopy , infrared spectroscopy , thin layer chromatography (TLC) , capillary electrophoresis (CE) , high‐performance liquid chromatography(‐mass spectrometry) (HPLC(‐MS)) , gas chromatography–mass spectrometry (GC/MS) , and laser desorption ionization–mass spectrometry (LDI‐MS) . Each method has its strengths and weaknesses.…”

Forensic Examination and Identification of Writing Inks on Documents

“…Micro spectrophotometer is used to overcome the problem of small availability of material in ink lines. This is not used as common method due to expense and complexity [10,15].…”

Análisis cromático y espectral de lacas acrílicas para retoque de pintura automotriz blanca mediante Reconocimiento de Pautas no Supervisado

“…El espacio de color CIELab es una transformación no lineal del espacio XYZ, cuyas coordenadas son L*, a* y b*, de acuerdo con la Figura 1 (Dubois, 2010). Este sistema se diseñó para que las diferencias en la percepción del color correspondieran a cambios equivalentes en estas coordenadas; actualmente se encuentran múltiples aplicaciones de dicho espacio en la literatura (Bouzidi et al, 2014;Feraru et al, 2015;Yi y Shamey, 2015 Cabe destacar que, en este y otros espacios de color, el blanco se considera un caso particular que presenta el máximo grado de luminosidad, sin saturación ni tono (véase Figura 1, con L* cercano a 100). El blanco encuentra un sinnúmero de aplicaciones comerciales, lo que ha llevado a la generación de múltiples tonalidades que requieren su 64 caracterización, constituyendo así un caso de particular interés para los coloristas.…”