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andrade6 - EXPERIMENT 6 LIQUID CHROMATOGRAPHY(FORMAL...

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EXPERIMENT 6: LIQUID CHROMATOGRAPHY (FORMAL) Introduction ___9___ / 10 pts Procedure ___4___ / 5 pts Data and Results ___22___/ 22 pts Properly labeled chromatogram of spinach extract. (6 points) Data table containing pigment name, observed color, and retention times from the chromatographic separation. (6 points) Table of R and α results. (5 points) Red cabbage extract acid-base results and observations. (5 points) Sample Calculations ____8__ / 10 pts Relative Retention (α) (5 points) Resolution (5 points) Discussion ___12___ / 12 pts Extraction and chromatography results. Discuss the observations you made upon adding the various drops of 0.1 M NaOH and 0.1 M HCl to the red cabbage extract. Chemically, discuss why changing the pH had an affect on the red cabbage extract. Problems and errors during the experiment. Observations and conclusions. 9 Questions (4 points each) ____26__ / 36 pts Style (organization, spelling, neatness, grammar, etc…) __5___ / 5 pts Other Deductions (i.e., Late Lab Report, incorrect formatting, etc…) - _____ Lab Report Score ___86__ / 100 pts
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The Extraction of Plant Pigments from Spinach and the Subsequent Separation and Analysis of the Extracted Pigments Using Liquid Chromatography Francisco Andrade Jessica Booe 5/12/10 Wesley Storm CHEM 241L 402, Morehead Labs Room 301 Pledge
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Introduction: The goal of this experiment is to extract the pigment from a prepared sample of spinach, and separate and analyze the pigments using reversed-phase liquid chromatography. A second part of the experiment that concerns the effects of pH on plant pigments will be investigated by adding 0.1M NaOH or NaCl to a prepared cabbage extract. These experiments will be carried out in order to learn about the process of liquid chromatography, and to learn about the pigments responsible for coloration in plants. The plan for studying the problem is to isolate the pigment molecules from spinach as much as possible, perform a liquid chromatographic extraction in order to separate the pigments from the rest of the organic matter in solution, and analyze the pigments and their distribution based on their polarity. The structure of plant pigments affects their polarity at the molecular level, and through reversed-phase liquid chromatography, one can analyze the pigments present in spinach. For example, chlorophyll a and chlorophyll b, two pigments which are responsible for the green coloration in plant leaves, are intermediate in polarity when compared with polar xanthophylls (yellow color) or carotenes (orange/red color) 1 . The spinach extract is a complex mixture suspended in a solvent, and by treating it with acetone, acetonitrile, and common table salt, one can isolate the organic compounds from the aqueous solution it is suspended in and create two phases: an upper organic phase containing the pigments and a lower aqueous phase. Liquid chromatography is useful because this method of separating molecules is
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This document was uploaded on 11/04/2011 for the course CHEM 241 at UNC.

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andrade6 - EXPERIMENT 6 LIQUID CHROMATOGRAPHY(FORMAL...

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