|
|
| Home > JCE Print > Journal of Chemical Education > Issues >
2004
>
March
> |
|
In the Laboratory
|
|
|
|
An Improved Method for the Extraction and Thin-Layer Chromatography of Chlorophyll a and b from Spinach
|
Hao T. Quach, Robert L. Steeper, and G. William Griffin
Science Department, Bunker Hill Community College, Boston, MA 02129
|
|
March 2004
Vol. 81 No. 3
p. 385
|
|
|
|
|
|
|
| Abstract |
|
A direct method of extracting plant pigments from spinach leaves into a dry organic solvent is presented. A powder is obtained by grinding a mixture of raw spinach, drying agent, and sand (1:1:2) that can be extracted directly into acetone in 10 minutes to provide a sample suitable for chromatographic analysis. This method avoids liquid–liquid extractions and subsequent drying as is found in previously reported methods. Removal of the magnesium ion from chlorophyll pigments was observed by treating the acetone extract with a strong ion-exchange resin for three minutes. The loss of magnesium ion is often observed as a degradation product of chlorophyll samples. An improved solvent system consisting of petroleum ether, cyclohexane, ethyl acetate, acetone, and methanol in 60%, 16%, 10%, 10%, and 4% quantities, respectively, is also reported. TLC separation using this extraction method and solvent system allows for the clear separation of chlorophyll a and b from all other extracted pigments.
|
| Supplement |
A copy of our laboratory handout and a list of chemicals and materials used in this experiment are available. We have also attached copies of figures that show how this method works for a number of green vegetables and extracts from dried and fresh spinach stored for extended periods of time to show the pigment degradation products.
|
 Contents |
|
| Download |
|
|
| More Information |
Citation |
Quach, Hao T.; Steeper, Robert L.; Griffin, G. William. J. Chem. Educ. 2004 81 385.
|
Keywords |
Chromatography; General Chemistry; Introductory / High School Chemistry; Laboratory Instruction; Natural Products; Plant Chemistry; Separation Science
|
History |
Created:
Last Updated: |
February 3, 2004
February 18, 2005
|
|
Link to Cover added (April 2004).
|
|
|
|
| Home > JCE Print > Journal of Chemical Education > Issues >
2004
>
March
> Page
385
|
|
|
| JCE HS CLIC |
|
Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
|
| Contributions Welcome |
| JCE welcomes your submission |
| Advertisers |
| In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first. |
| Be An Ambassador |
| Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants. |
|
