The Identification And Classification Of The Red Ball-point Pen Ink

Ink analysis takes very important part in forensic science. Most of its applications involve the detection and discrimination of alterations to documents with significant financial value such as counterfeit banknotes, tax returns, insurance claims, receipts and wills.The paper included six parts:In chapter one, it was summarized the recent advance of questioned documents and dating writing inks, including spectroscopic analysis, chromatography analysis, mass Spectrometry.In chapter two, it was described the important components, and analyzed red ballpoint pen inks by ultraviolet-visiable photography. The red ballpoint pens studied were divided into three categories according to the UV-Vis spectrograms.The red ballpoint pen inks were divided by electrochemical mehod in chaper three. The buffer solution and extract amount were discussed.The red ballpoint pen inks studied were separated into 8 kinds by thin layer chromatography (TLC) in this chaper. The retardation factor, R_f value of a compound of ink was dependant on the absorbent and mobile phase, and the number and color of spots can be used to identify the difference among the inks.In chapter five, the red ballpoint pen inks were analyzed by high performance liquid chromatography (HPLC). The selected proper extractor, mobile phase, the reproducibility, detector limit and the effect of different paper were studied.The red ballpoint pen inks were analyzed by high performance liquid chromatography- mass Spectrometry (HPLC-MS) in chaper six, mainly studied the unkown spots in TLC and unknown peaks in HPLC.This study provides useful information for the determination of writing time and aging study of red ballpoint pen.