This exercise sets up a collaborative activity that challenges students to develop a chromatographic solvent with the appropriate polarity to separate leaf chlorophyll and anthocyanin pigments by TLC. The suggested activity has been tested with both high-school advanced-chemistry students and with undergraduate students in an introductory biochemistry class. It includes a demonstration introducing the basic principles of partitioning and differential distribution based on solubility. For the student activity, the materials to be used are leaves of the variegated Coleus plant, plastic-backed silica TLC plates, 2-propanol, acetone, and methanol. Students may work collaboratively within a set of boundary parameters to optimize the chromatographic solvent through a series of rapid iterations of chromatography. Students can also use these chromatography systems to carry out independent projects.
More Information
Citation
Curtright, Robert D.; Emry, Randy; Markwell, John. J. Chem. Educ.1999 76 249.
Keywords
Biochemistry; Laboratory Instruction; Chromatography; Natural Products; Separation Science; Undergraduate Research
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.
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.
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.
For journals in other fields of chemistry visit ACS Publications.
Citation
Always in the