This document discusses the examination of ink and paper. It describes how chromatography, including HPLC, TLC, and paper chromatography, can be used to physically separate the components of inks. It also discusses how paper chromatography was used to characterize two samples of black ink from different manufacturers by measuring their retention factors. Additionally, it lists some differences between papers that can be examined, including raw material, weight, density, thickness, color, watermarks and age. Finally, it poses some frequently asked questions about obliterations and infrared luminescence.
2. Ink
1. Chromatography is a method
of physically separating the
components of inks.
2. Types
– HPLC—high-performance
liquid chromatography
– TLC—thin-layer
chromatography
– Paper chromatography
3. Paper Chromatography of Ink
Two samples of black ink from two different manufacturers have
been characterized using paper chromatography.
4. Retention Factor (Rf)
1. A number that
represents how far a
compound travels in a
particular solvent
2. It is determined by
measuring the distance
the compound traveled
and dividing it by the
distance the solvent
traveled.
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