Separation of Photosynthetic Pigments by Paper Chromatography
Introduction
Chlorophyll is in fact only one pigment in a group of closely related
pigments commonly found in photosynthesising plants called
photosynthetic pigments. This can be demonstrated by extracting the
pigments from leaves with acetone and separating them by means of
paper chromatography. With a bit of luck five pigments can be
identified: chlorophyll a (blue-green), chlorophyll b (yellow-green),
xanthophylls (yellow), carotene (orange) and phaeophytin (grey, it is
a breakdown product of chlorophyll).
Absorptive paper with a concentrated spot of leaf extract is used in
this experiment. When dipping in a suitable solvent, the pigments
ascend the absorptive paper at different rates because they have
different solubilities in the solvent. In this way they become
separated from one another and can be identified by their different
colours and positions.
Requirements:
l Large test tube (24 * 150 mm);
l Stopper to fit test tube;
l Pin;
l A small glass tube to transfer pigment solution;
l Chromatography paper or filter paper;
l Rack of test tube;
l Pigment solution;
l Solvent (5 cm3).
Procedure:
l A strip of absorptive paper has been prepared. It has such a length
that it almost reaches the bottom of a large test tube and such a
width that the edges do not the sides of the tube;
l Draw a pencil line across the strip of paper 30 mm from one end. The
paper has been folded at the other end through 90 degrees and attached
to the stopper using a pin. Take care not to let the lower end of the
paper touch the bottom of the tube or edges touch the sides;
l Remove the paper from the boiling tube and use the small glass tube
provided, place a drop of the pigment solution at the centre of the
pencil line. Dry the spot under the heat from a hairdryer or let it
dry naturally. Place a second small drop on the first.
Compress the safety bulb, hold it firmly against the end of the pipette. Then release the bulb and allow it to draw the liquid into the pipette.
rings on the ends of the cinch. Next, take the two d-rings in the center of the cinch and with your
The results for the various conditions differed dramatically. As seen in the table, “Data Collected During Time Interval” the reference test tube remained at a trasmittance level of 100% for all five experimental tests. The control solution remained fairly constant for all five tests, but did vary slightly after the five minute time interval.
move no more than the width of the folded side of a piece of paper seen
Experiment #1: The purpose of this experiment is to investigate the effects of baking soda and light intensity on the rate of photosynthesis of green spinach leave through the observation of floating disk.
Chromatography has been developed over the past century and has an important contribution in many areas of modern science. However the main original work of M.S.Tswett was published in a book Chromatographic Adsorption Analysis.
Spectrophotometry is a widely used method to calculate how much light is absorbed by a chemical substance. This is done by measuring the intensity of light as it passes through a sample solution. The principle of this method is that a compound absorbs or transmits light over a certain wavelength from which the measurement can be used to calculate the concentration of a known chemical substance.
Pigments produced by microorganisms has been used to dye fabrics of different types. Talaromyces verruculosus produce a red colored pigment which is suitable to dye cotton and is harmless. Pigments from microorganisms give different types of shades of a color. For instance; Janthinobacterium lividum produce a pigment which gives purplish-blue shade to different types of fabrics. Thermomyces produce a yellow pigment used to dye number of fabrics specifically silk. NP2 and NP$ strains of Streptomyces produce dark blue and red colored pigments. Among retaining dye of microbial strains cotton fabric were stained comparatively weak while acrylic and polyamide fibers stained strongly.
Analysis of Amino Acids by Paper Chromatography Introduction- Proteins may be thought of natural polymers of amino acids, as the composition of proteins is of amino acids. The technique known as paper chromatography is used to separate amino acids for analysis. In this technique small spots of amino acids are introduced to a piece of porous filter paper.
through it. It goes so quick, though, that it does not hurt much. I bind the finger up with a piece of cotton and go on working. We all have accidents like that.
Step 4:Make sure the person holds the clothespin between their thumb and index finger and squeeze until the two ends meet.
If I were using a cut out of length 1cm, the equation for this would
paper that has a black cross drawn on it. I will then measure 15cm³ of
thickness 34 mm and length 30 cm at the same point on the ends of the
Write down the following problem using a pencil and a sheet of paper: (See Figure 1)