Teachers First - Thinking Teachers Teaching Thinkers

Ink Analysis Lecture Notes

What is in ink?

· Several organic dyes - blue, red, black, etc. (This can form an ink "fingerprint.")
· Tags that signify the manufacturing year - isotopes
Why is ink important forensically?
· Fraud cases
· Embezzlement
· Theft
· Kidnapping and Ransom
· Threats
· Documentation

How is ink used as a forensic tool?

· A small sample is dissolved.
· This sample is compared to a known sample.
· Each pen manufacturer has its own "recipe" for ink, so a sample from a document can lead to the discovery of the type of pen used.
· The tags in ink can determine the year the pen was manufactured.

What is thin layer chromatography (TLC)?

· Qualitative analysis.
· Separates mixtures into individual parts.
· "Like dissolves like" - polar vs. non-polar.
· Mobile phase vs. stationary phase.