Goal: The goal of this lab is to determine the composition and identity of an unknown hydrocarbon mixture using gas chromatography (GC). You will do this by first running a hydrocarbon standard through the instrument and then running your unknown through the same instrument. A comparison of your data to the standard data will allow you to draw appropriate conclusions.
Procedure:
1. Your instructor will explain the proper settings used for the gas
chromatographs.
2. Inject the standard alkane mixture onto the column . This mixture
contains the straight chain alkanes octane through dodecane.
3. Calculate the retention time (tR) for each component of
the standard mixture.
4. Inject your unknown sample onto the column. Record your
unknown letter in your lab book.
5. Calculate a tR for each of your unknown’s
components and the % composition of your sample.
6. Determine the composition of your unknown by comparing it to the
standard data you have calculated.
| Chemical Information | |
| Name | Structure (2-D) |
| octane |  |
| nonane |  |
| decane |  |
| undecane |  |
| dodecane |  |