CHEM 219
Lab Report & Lab Notes
Experiment #: 5 Column Chromatography
Portage Learning
Inside you will get:
- Clear, Concise Scientific Language.
- All Tables and Figures Labelled Clearly.
- Included Units for All Measurements.
- Proofread Report.
- Portage Learning.
, Chemistry Lab Report
Experiment #: 5
Title: Column Chromatography
Purpose: To perform a solid-liquid extraction to isolate a solution of colored pigments
from a sample of spinach then to use column chromatography to separate the extract
and isolate the two major classes of pigments (chlorophylls; carotenoids). We will use
column chromatography to confirm the efficiency of the separation in the column.
Procedure:
1. Tear up 3.5g of fresh spinach leaves into a mortar.
2. Add sodium sulfate powder (drying agent to draw the moisture from the leaves).
3. Add sand (macerating agent) to help grind up the spinach to break up the cells
and release the pigment.
4. Use a pestle to macerate/grind the mixture. Add small additional quantities of
each of the substances to try to achieve a dry powder form of the spinach.
5. Add the spinach extract to a flask where we will extract the spinach pigments into
a small quantity of acetone. Add acetone to the flask with the spinach extract,
add a cap, gently mix, and allow the acetone to extract pigments for a few
minutes.
6. Decant the extracted pigments from the original powder by pouring the
pigmented liquid into an empty flask. Wash the powder with more acetone to
make sure most of the pigment is extracted.
7. Place the pigment solution into a warm water bath and blow a stream of dry
nitrogen gas across the top to speed the evaporation and protect the solution
from air.
8. Take a small sample of the raw extract with a microcapillary tube and apply a
spot onto a thin layer chromatography plate (used later to check the
effectiveness of the chromatography column).
9. Load the sample onto the prepared column using a pipette. Use small quantities
of hexane solvent to facilitate the transfer.
10. Open the stopcock at the bottom of the column and run the sample down into the
sand layer.
11. Allow the solution to move through the column. Once you witness the
yellow/green separation, stop the flow of solvent and fill the column with hexane
and proceed with the separation.
12. Since the keratein fraction has alluded out, stop the flow, change out the flask,
and change out the composition of the solvent to a solution that is more polar
(70% hexane, 30% acetone). Add the solution to the column.
13. Add most polar solution (20% methanol, 80% acetone) to get it to move faster.
14. We have now collected the keratein fraction (yellow) in one flask and the
chlorophyll fraction (green) in another flask.
This study source was
Chem219Exp5docx/
Lab Report & Lab Notes
Experiment #: 5 Column Chromatography
Portage Learning
Inside you will get:
- Clear, Concise Scientific Language.
- All Tables and Figures Labelled Clearly.
- Included Units for All Measurements.
- Proofread Report.
- Portage Learning.
, Chemistry Lab Report
Experiment #: 5
Title: Column Chromatography
Purpose: To perform a solid-liquid extraction to isolate a solution of colored pigments
from a sample of spinach then to use column chromatography to separate the extract
and isolate the two major classes of pigments (chlorophylls; carotenoids). We will use
column chromatography to confirm the efficiency of the separation in the column.
Procedure:
1. Tear up 3.5g of fresh spinach leaves into a mortar.
2. Add sodium sulfate powder (drying agent to draw the moisture from the leaves).
3. Add sand (macerating agent) to help grind up the spinach to break up the cells
and release the pigment.
4. Use a pestle to macerate/grind the mixture. Add small additional quantities of
each of the substances to try to achieve a dry powder form of the spinach.
5. Add the spinach extract to a flask where we will extract the spinach pigments into
a small quantity of acetone. Add acetone to the flask with the spinach extract,
add a cap, gently mix, and allow the acetone to extract pigments for a few
minutes.
6. Decant the extracted pigments from the original powder by pouring the
pigmented liquid into an empty flask. Wash the powder with more acetone to
make sure most of the pigment is extracted.
7. Place the pigment solution into a warm water bath and blow a stream of dry
nitrogen gas across the top to speed the evaporation and protect the solution
from air.
8. Take a small sample of the raw extract with a microcapillary tube and apply a
spot onto a thin layer chromatography plate (used later to check the
effectiveness of the chromatography column).
9. Load the sample onto the prepared column using a pipette. Use small quantities
of hexane solvent to facilitate the transfer.
10. Open the stopcock at the bottom of the column and run the sample down into the
sand layer.
11. Allow the solution to move through the column. Once you witness the
yellow/green separation, stop the flow of solvent and fill the column with hexane
and proceed with the separation.
12. Since the keratein fraction has alluded out, stop the flow, change out the flask,
and change out the composition of the solvent to a solution that is more polar
(70% hexane, 30% acetone). Add the solution to the column.
13. Add most polar solution (20% methanol, 80% acetone) to get it to move faster.
14. We have now collected the keratein fraction (yellow) in one flask and the
chlorophyll fraction (green) in another flask.
This study source was
Chem219Exp5docx/
