Org Chem Liquid Phase Chromatography

Experiment 4 – Liquid Phase Chromatography
I. Objectives
This experiment’s goal is to explore one-dimensional and two-dimensional paper chromatography.
II. Schematic Diagram of the Procedure
PAPER CHROMATOGRAPHY
Wash leaves, cut them into smaller pieces; in a mortar macerate them in circular motion

Add 8mL ethyl alcohol to extract pigments, continue macerating until finely grounded

Transfer extract to evaporating dish, allow to conc, don't let extract to dry out Concentration may de done by boiling off some solvent with hot plate or hair blower

Allow solvent to dry and dab another extract Dab extract onto chromatographic paper, along 4mm of starting line, using capillary tube

Draw two lines: (1) starting line 1.5cm above V point, (2) finish line 1cm below other end

Cut strip of chromatographic paper (1cmx10cm), cut one end into Vshaped edge

Repeat dabbing 58times to build up concentrated spot

Put 2mL chromatographic solvent into 6" test tube Bend paper clip, attach to cork stopper; attach paper strip, this should not touch the glass

Watch solvent rise up the paper, carrying and separating the pigments as it goes

Calculate Rf of each pigment Measure distances travelled by pigments and solvent Mark boundaries and center of colored streaks using pencil

When solvent reaches top, remove paper and let it dry

Using same chromatography paper, visualize other possible pigments in test tube chamber cont. iodine crystals

Note appearnce of brown pigments, remove from chamber, mark with pencil, calculate Rf

Label paper chrom and submit to instructor III. Table of Reagents/Products (MSDS-material safety data sheet)
Rgt/Pdt

Structure

Physical Properties

Hazards

Ethanol

Boiling Point: 78.5°C
Melting Point:-114.1°C
Density: 0.789g/mL
Appearance: Clear, colorless liquid

Acetone

Boiling Point: 133°F
Melting Point: -137.2°F
Density: