Ink Analysis and Thin Layer Chromatography (TLC) Lesson Plan
1. To introduce students to thin layer chromatography.
2. To introduce students to the component parts of ink.
3. To provide students with an opportunity to apply science with laboratory
1. Students will be able to explain the process of
2. Students will be able to identify at least three components of ink.
3. Students will be able to analyze data and make conclusions based
on laboratory observations.
1. Lab Handouts
3. Lecture Notes
4. 3 sources of ink (Same color) - Bic, Papermate, and Sharpie brands
could be used
5. Sample Writings
6. Chromatography Paper
9. 2:1 propanol:water
10. Petri dishes (half per group)
11. Plastic Cups - disposable (1 per group)
14. Water alcohol mix to extract ink
1. Journal entry or Warm-up question: "What is
ink made of/"
2. Set up crime scene - "A check was stolen from the principal's
office yesterday. The check later showed up in the athletic office.
The principal always uses the same ink pen to write checks. Two suspects
have been found. Your task is to analyze the ink pens of the principal,
the suspects, and three known samples. You will compare, by thin layer
chromatography, the component parts of the ink. With this information,
you will be able to determine who stole the check from the principal's
1. Complete anticipatory set as described. (Day 1)
2. Hand out TLC Lab Sheet.
3. Collect samples from the forged check.
4. Set up TLC as a class. The teacher should model each step, and then
the students will repeat the procedure. The class will move on together.
5. Hand out lecture notes and discuss the characteristics of ink and
TLC. (Move onto next step after 20 minutes regardless of progress with
6. Set chromatography paper out to dry.
7. Finish notes if needed.
8. Analyze TLC findings. (Day 2)
9. Answer lab questions.
10. Handout homework worksheet.
11. Assist students as needed with the TLC analysis.
1. The lecture can be adapted by providing learning
support and lower ability students with a partially completed set of
lecture notes. Higher ability students may either be required to fill
in more of the lecture notes or may be required to take all notes by
2. No adaptations are required for the lab activity because the lab
groups are cooperative and mixed ability.
1. Day 1 - Students list the steps of TLC on a piece
of paper. This paper will be turned in at the door as the exit pass
from the room.
2. Day 2 - Students, remaining in their lab groups, discuss why the
different black pens produced different chromatography charts.
1. Students will conduct a lab that will reinforce
the lecture information.
2. Students will have a homework assignment that uses information obtained
from the lab.
1. Students will be evaluated by their lab handout and homework.
2. Students will be evaluated by the final unit project.
1. Students will be expected to receive an 80% or
higher on their lab and homework.
2. The lesson will also be evaluated at the end of the unit. Students
will be expected to receive an 80% or higher on the final lab report.