6_chromatography_post_lab, Lab Reports of Chemistry

Download 6_chromatography_post_lab and more Lab Reports Chemistry in PDF only on Docsity! POST-LAB QUESTIONS - Chromatography Name ABDULLAH ALQARAGOLI Connecting concepts to real-world 1. Scenario: The FBI is investigating a financial crime and they found a piece of critical evidence which is a check written by the criminal. There are currently five suspects under investigation in this case. Each one of them carries a differently-designed pen as shown in the figure below. Use TLC techniques to design an experiment to identify the criminal who actually wrote the forged financial document. Gather all the pens belonging to the suspects which have identifying marks on them for sampling and identification purposes. Ink Sample Collection: Collect ink samples from each of the five suspects' pens that were collected initially, ensuring that there is sufficient ink for the thin-layer chromatography (TLC) test. TLC Plate Preparation: Make multiple TLC plates and cut them into rectangular shapes. Clean the plates using solvents like ethanol to eliminate any impurities. Develop TLC Plates: Submerge the plates into a chamber containing a solvent that is appropriate for the type of ink samples being tested. The solvent will carry ink components as it travels up the plate. The specific solvents used will vary based on the type of ink being tested. TLC Plate Visualization: Take the plates out of the developing chamber once the solvent has traveled a specific distance. Let the plates dry for some time, and then visualize the ink components by using UV lights. Analysis of TLC Results: Compare all five TLC plates with the ink sample on the forged financial document, and observe similarities and differences such as the number of spots and their position on the plate. 2. The FBI agency run the TLC experiment for the following 6 samples. Spots 1-5 are corresponding to five pens listed above. Spot 6 is the sample extracted from the signature on the back of the check. Based on the results shown in the picture below, measure the distance traveled by each spot and calculate the Rf values. 3. Based on the results, identify the person who wrote the forged check (suspect 1-5). Please provide the reason and explain why he/she is the suspect.