|
|
| 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
|
|
|
| Chemistry Teacher Connection |
|
The "Chemistry Teacher Connection" (CTC) is especially for high school chemistry teachers. For only $40/year, it offers an online-only subscription to CLIC along with membership in the Division of Chemical Education, normally $65/year. CTC subscribers receive access to all articles and supplements from 1996 through the current issue.
|
| C&EN CLICs |
|
Through special arrangement with the ACS, JCE High School CLIC is now able to provide subscribers with online access to Chemical & Engineering News articles that have been selected specifically for secondary science instructors and their students.
|
JCE Collections Available
|
Occasionally, collections of JCE back issues become available for donation to individual teachers, schools, or libraries. JCE matches collections with interested recipients. Recipients pay shipping costs or pick up the collection.
|
| Contributions Welcome |
| JCE welcomes your submission |
| Fishing for New Ideas |
 Always in the
process of
improving, CLIC
welcomes ideas and comments.
Email Us |
|
