CHE 311 "Chromatography"

Your lab report should follow the format and consist of the following:

Title (be specific)

Your Name

Date

Section Number (CHE 311-0X)

1. Introduction:

• Purpose of Experiment
• Important theory and/or background material
• Structures and/or reactions
• Approproate references to literature (if necessary).

2. Methods / Materials: Usually a simple list, but make sure it is accurate and complete.

3. Experimental Procedure:

• Describes the process in chronological order
• Explain all of the steps in the order they actually happened, NOT as they were supposed to happen.
• If you've done it correctly, another researcher should be able to duplicate your experiment.
  

4. Results and Discussion:

• Results are usually dominated by calculations, tables and figures; however, you still need to state all significant results explicitly in verbal form.
• Discussion focuses on a question of understanding, "what is the significance or meaning of the results?".

Make a table showing the R_f values for each component for each adsorbent.

5. References and Post-Lab Questions:

a. Two components, A and B, were separated by tlc. When the solvent front had moved 10.0 cm above the level of the original spot, the spot corresponding to A was 3.5 cm and that of B was 4.1 cm above the original spot. What are the retention factors for A and B? Which component would elude first from a column chromatography using the same absorbant and solvent?

b. Describe how thin layer chromatography could be used to analyze a urine sample for the presence of cocaine if you had a known sample in the lab.

c. Why is it important that the sample to be analyzed by tlc be dry?

d. Why must the solvent level be below the original spot on the tlc plate?

e. Why must the cap be in place on the bottle during the tlc separation?

GLC

1. Introduction:

• Purpose of Experiment
• Important theory and/or background material
• Structures and/or reactions
• Approproate references to literature (if necessary).

2. Methods / Materials: Usually a simple list, but make sure it is accurate and complete.

3. Experimental Procedure:

• Describes the process in chronological order
• Explain all of the steps in the order they actually happened, NOT as they were supposed to happen.
• If you've done it correctly, another researcher should be able to duplicate your experiment.
  

4. Results and Discussion:

• Results are usually dominated by calculations, tables and figures; however, you still need to state all significant results explicitly in verbal form.
• Discussion focuses on a question of understanding, "what is the significance or meaning of the results?".

Fill out the table:

stationary phase: carbowax

column temperature:

carrier gas: air

detector: TCD

	Retention Time (sec)	Height (cm)	Width @ 1/2 Height (cm)	Area (units)	Calculated Weight %
4-methyl-2-pentanol
4-methyl-2-pentanone
Unknown Peak 1
Unknown Peak 2

5. References and Post-Lab Questions:

a. In a glc three peaks are observed and their areas are calculated as follows: A, 13.5 mm²; B, 20.2 mm²; C, 4.6 mm². What is the % composition of each component in this mixture?

b. Describe how the identity of each of the components could be determined if known samples of two of the compounds were available.

c. In the known 50%/50% mixture of alcohol and ketone, why are the areas of the two peaks not equal?

© Dr. Noel Sturm 2014