Cromatography and Detergents
Question 1:
You have carried out an investigation into the pigments that make up chlorophyll.
Use the chromatogram you obtained when carrying out this investigation. Clearly explain the separation technique of paper chromatography in terms of partition.
Calculate the Rf value of one of the constituent pigments and compare it to the book value.
A paper chromatography was used to separate the pigments that make up chlorophyll to analyse, identify, and quantify the components, using paper (stationary phase – the part of the apparatus that does not move with the sample) and chromatography solvent that was 90% petroleum ether and 10% propanol (mobile phase – liquid that carries the components).
A light pencil line is drawn across the strip of paper (about 2cm from one end) and the other is attached to the splint, making sure that the paper doesn’t touch the bottom of the beaker.
The leaf is placed into boiling water for a minute and then mortared with a pinch of sand and a few drops of propanone to allow the extraction of the chlorophyll solution with a capillary tube.
Two small dots of chlorophyll solution are placed on the pencil line on the chromatography paper. After the dots were dry a second dot was placed on top of the first couple, this process was repeated five times.
A small amount of solvent was then placed into the bottom of the beaker, the paper suspended in the container, the solvent level below the pencil line; therefore the compound was placed on the stationary phase. The beaker was covered to the solvent wouldn’t evaporate.
The solvent was left to pass through the paper for some time and then removed from the beaker and the distance travelled was marked and recorded (6.6cm). That point is the solvent front.
The mobile phase dissolved the components and carried the individual pigments though certain distances, that distance was different to each pigment and the mixture was separated into different coloured spots.
Some components in the
You have carried out an investigation into the pigments that make up chlorophyll.
Use the chromatogram you obtained when carrying out this investigation. Clearly explain the separation technique of paper chromatography in terms of partition.
Calculate the Rf value of one of the constituent pigments and compare it to the book value.
A paper chromatography was used to separate the pigments that make up chlorophyll to analyse, identify, and quantify the components, using paper (stationary phase – the part of the apparatus that does not move with the sample) and chromatography solvent that was 90% petroleum ether and 10% propanol (mobile phase – liquid that carries the components).
A light pencil line is drawn across the strip of paper (about 2cm from one end) and the other is attached to the splint, making sure that the paper doesn’t touch the bottom of the beaker.
The leaf is placed into boiling water for a minute and then mortared with a pinch of sand and a few drops of propanone to allow the extraction of the chlorophyll solution with a capillary tube.
Two small dots of chlorophyll solution are placed on the pencil line on the chromatography paper. After the dots were dry a second dot was placed on top of the first couple, this process was repeated five times.
A small amount of solvent was then placed into the bottom of the beaker, the paper suspended in the container, the solvent level below the pencil line; therefore the compound was placed on the stationary phase. The beaker was covered to the solvent wouldn’t evaporate.
The solvent was left to pass through the paper for some time and then removed from the beaker and the distance travelled was marked and recorded (6.6cm). That point is the solvent front.
The mobile phase dissolved the components and carried the individual pigments though certain distances, that distance was different to each pigment and the mixture was separated into different coloured spots.
Some components in the