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Lecture 14. IR & 1 H NMR Practice Problem (Lec 13) Column Chromatography of Plant Pigments Get Lecture Problem 5, due next class. This Week In Lab: Ch 7 PreLab Due Quiz 4 Ch 5 Final Report Due Next Week in Lab: Ch 9 PreLab Due Quiz 5 Ch 6 Final Report Due. Chapter 9
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Lecture 14 • IR & 1H NMR Practice Problem (Lec 13) • Column Chromatography of Plant Pigments • Get Lecture Problem 5, due next class • This Week In Lab: • Ch 7 PreLab Due • Quiz 4 • Ch 5 Final Report Due • Next Week in Lab: • Ch 9 PreLab Due • Quiz 5 • Ch 6 Final Report Due
Chapter 9 Column Chromatography of Plant Pigments A two-day experiment Day One - Extraction & Chromatography of Plant Pigments Day Two - UV/VisAnalysis of Plant Pigments
Extraction of Plant Pigments • Obtain spinach leaves • Grind up leaves with acetone, petroleum ether and CaCO3 • Transfer to a separatory funnel • Extract (similar to Ch 5!) • Organic layer contains plant pigments - to be separated via column chromatography
Column Chromatography of Plant Pigments • Pack column • Load sample (plant pigment solution/organic layer) to column • Run column & collect fractions in tared flasks • **NEVER let the column to dry** • Always have fresh mobile phase in the column • TLC the fractions • See video on column prep in class.
Column Chromatography Of Plant Pigments: Step 1 Getting the column ready http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/D-CC-e.htm
What the column will look like - the colored bands are the plant pigments! Running the column & collecting fractions http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/D-CC-e.htm
Finishing up & Evaluating the fractions The different fractions That contain the Different pigments Evaluate by TLC & By UV/Vis http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/D-CC-e.htm
Carotenoids • Hydrocarbons • Orange/red/yellow pigments in fruits and veggies • Conjugated p systems • Involved in photosynthesis
Chlorophylls • Porphyrins • Blue/green pigments in plant leaves • Also involved in photosynthesis • Produced by plants in response to sunlight
Flavonoids • Aromatic compounds • Red, violet, blue, or yellow pigments in plants, fruit, flowers • In fruit and flowers, act as an attractant for insects to distribute pollen and seeds • In leaves, act as sunscreens