What is thin layer chromatography used for in document examination?

Thin layer chromatography (TLC) is primarily utilized in document examination to separate and analyze the components of inks. When two inks are suspected to be the same or different, TLC allows forensic experts to identify the specific pigments and solvents present in each ink sample. This process involves applying small samples of the inks onto a stationary phase and developing them with a solvent, which causes the different components of the inks to travel at varying rates, effectively separating them.

By comparing the resulting chromatograms of the inks, examiners can observe differences in the components, which assists in determining whether the inks share a similar composition or originate from different sources. This capability is essential in forensic science, as it can provide evidence in cases involving questioned documents, fraud, or other criminal activities where authenticity is in doubt. Thus, the answer accurately reflects the practical application of TLC in distinguishing between inks in a document examination context.