NCJ Number
183894
Journal
Journal of Forensic Sciences Volume: 44 Issue: 6 Dated: November 1999 Pages: 1204-1214
Date Published
November 1999
Length
11 pages
Annotation
This article reports on the destructive identification of ballpoint pen ink by using field desorption mass spectrometry (FDMS) to determine the basic dyes in the ink.
Abstract
Seven different brands of black, blue, and red ballpoint pen inks (21 samples) were examined in this study. A 1-mm section was cut from an ink line drawn on paper and used as the sample. Extraction was performed with methanol. Analysis of each extract by FDMS showed the molecular ion peak of each dye, and the black, blue, and red inks were then classified into six, six, and six types, respectively, based on the ions detected. Study results indicate that FDMS can be a valuable tool for analyzing ballpoint pen ink. The basic dyes used in these inks have a nonvolatile character, and this property makes it difficult to analyze them by electron impact and chemical ionization. By using the FDMS method, it is possible to estimate the manufacture based on the molecular ions and specify a dye from the mass number. The method further shows that ballpoint pen ink is constituted from several kinds of dyes; therefore, it is possible to distinguish whether the ink in various writing samples is the same. Making a database of such ink products could facilitate the identification of the pen's manufacturer. An ink line 1 mm in length was found to be sufficient for analysis. 13 figures, 3 tables, and 9 references