As stated before, there is a mobile phase and a stationary phase. The water that hydrogen bonds with the hydroxyl groups acts as the stationary phase. The mobile phase is the liquid moving through the pores in the paper. Paper chromatography is carried out as follows. Samples of ink or dye are placed on the paper and distributed evenly.
Then, the paper is rolled and stapled. The bottom of the paper where the samples are is submerged in a solution. This solution can vary as you will see in the procedure. The sample will then spread. The more polar the substance is, the less it will spread.
After the process is complete R f samples can be determined. R f stands for retention factor and it is basically a way of finding how polar the sample is. It is the distance moved by the component divided by the distanced moved by the mobile phase front. The mobile phase front is basically where the farthest component has travelled.
Therefore a very nonpolar substance will have an R f of close to one while a very polar substance will have a very small R f value. In this laboratory, paper chromatography was used to identify ink samples. However, there are many other methods that identify ink samples. Capillary Electrophoresis is one.
Microscopy is exactly what it sounds like. Using a very strong magnifying lens, ink samples can be compared to others without actually putting the sample in a chemical test.
This reveals the chemical makeup of ink quicker than ever. In this lab, the goal was to create a solution of the most ideal polarity to send chromatographs through. After a standard amongst the group was found the best looking sample two solutions in which our chromatographs were submerged was agreed upon.
After we received unknowns our goal was to put it through chromatography and identify the ink samples with the standard we agreed upon. To achieve best results and have the best chance to identify unknowns, the stationary phase must be as polar as possible without being just water. Therefore, 1 part methanol, and 2 parts water should yield a polar solution that will not allow our ink sample mobile phase to travel as far.
This solution of 1 part methanol and 2 parts water will have a polarity of 8. When the original chromatograph was made using different food dyes this will be explained in the Procedure section the polarity was 5.
Therefore, the more polar the stationary phase is, the less distance travelled, and the better the results will be. Before any unknowns were identified and any solutions made, we had to first understand how chromatography worked. Section A helped prepared us to do just that. The first step was to get one piece of chromatography paper and label it. To label it I had to measure 0. Then I measured every 1 cm and put a hash mark. A capillary tube was made for the transfer of dyes and were placed on each hash mark.
I then made a cylinder out of my paper and stapled it leaving a slight gap. I made a solution of 2: The paper was then placed in the solution with the mobile phases closest to the solution and placed a cup over it. The process took about minutes until it was complete. When the paper was dried the solvent front was determined and the R f values were found. It was from this part of the experiment that I realized the ink has spread too far and that a different solution needed to be made.
I was also able to identify all the components of the dyes that were made up of more than one. He made the dye because we shared the dyes and samples initially. The samples that a mixture of components were determined solely by the R f values. This was the gateway to creating my own solution to determine the unknown samples.
Initially each member of the group, Grei, Ryan, Chris, and I made one. It is noted that we did not necessarily pick random combinations of water and an alcohol.
The Snyder Index gives relative polarity values up to 9. Water has the value of 9 and it is the most polar. See Table 1 below for the Snyder index To determine polarity by the Snyder index, the values of each part are added up and divided by the number of parts in the solution. Ryan made a solution of 6.
I made a sample of 8. Chris made a solution of 8. After making a chromatograph and listing putting a sample of each of our 15 pens we ran the first test. After the testing was done, we each did one more test with different polarities that we thought would be better based on our first polarities.
This time I made a solution of 8. Grei ran a 7. Ryan ran a 7. Lastly, Chris ran a 7. I will begin by showing the results of the very first chromatograph ran and briefly describing what was seen.
I will move on to each chromatograph in order until are shown and briefly explained. I will also show the initial list of different dyes such as the cheddar cheese and the Kool-Aid just to show that R f values can be useful, however, they were not useful in the ink experiment.
Samples from left to right were all food dyes and combinations. As you can see the 2: This is why the different solutions were to be made.
Also the dots show where to measure for the R f values. In all the chromatographs made, the ink samples are in order from the left to right with the following inks listed in table 3.
Chromatograph 4 was the standard that Ryan made. It had a 6. Chromatographs 6 and 7 were my unknowns with 6. The following chromatographs six and seven were the unknowns that I ran with a polarity of 6.
The initial chromatograph was carried out to understand how to run chromatography, to understand how to use R f values, to identify the components of substances such as Cheddar Cheese and Kool Aid, but most importantly to see that the ink samples are too difficult to measure with the polarity of the solution we used.
Referring to table 2, we can see all the dyes, inks, and substances that were carried out. This was not vital to the experiment so I will not go into great detail about it. However, it shows that the R f values are unmeasurable for the most part for the ink samples. Table 3 shows the ink samples are they are put on chromatographs in order from left to right.
As you can see there are three different colors of ink and 5 different brands. At last, the first chromatograph chromatograph 2 vital to this experiment was ran. This has 1 part methanol, and 5 parts water. Its polarity was 8. As one could tell many of the samples did not move whatsoever. I would never use that chromatograph if I was working alone because some did not move, and if you look at Pilot Vball Black, it shifted to the right.
This suggests human error. It was disturbed during the chromatograph process. Nonetheless, the ones that did not move were very polar just like the stationary phase.
If one recalls, the distance traveled by a sample increases and polarity decreased. More simply put, if a sample is nonpolar, it will be higher up on the chromatograph.
Through capillary action these pigments will travel up the paper until the bonds between the water and pigment become so weak that the pigment must break the attraction and leave itself imprinted at a certain height up the paper. Therefore, they will remain at the concentrated area unless a lipid soluble solvent is present.
If this lipid soluble solvent is present, as opposed to the water soluble solvent, then the lipid soluble pigments will move up the chromatography paper instead of the water soluble pigments. The same idea will happen. The lipid soluble pigments will travel up the paper until their bonds between the water are so weak that it must stop following the movement of the solvent, and get placed at a certain height above the original concentrated dot.
Spinach will have mainly chlorophyll A and B because the leaf is completely green, compared to the beat leaf which consists of both a red and green shade showing that other pigments are present in this leaf.
A certain solvent will only attract certain pigments up the paper. For example this experiment used water soluble and lipid soluble solvents.
This means that when one of these solvents are present in the trial, only that type of pigment will travel with the movement of the solvent lipid soluble solvent with lipid soluble pigment and water soluble solvent with water soluble pigment. The beat leaf contained more pigments in the leaf compared to the spinach leaf.
This could be because the beat has a root where it stores starch. This would require it to undergo photosynthesis more times in order for its to create more glucose to store.
Paper Chromatography Experiment Report Type of paper: Research Papers Subject: Medicine Words: Introduction lab coat, filter paper, toothpick, ninhydrin solution, mixtures to be identified and known amino acids. Discussion/Analysis. The collected data .
paper chromatography report. Paper Chromatography: Introduction The materials used for this lab are paper, pencil, eraser, filter paper, test tube, rubber stopper, paper clip, metric ruler, black felt-tip pen, and a computer. Methods.
Paper chromatography experiment 1. Clarinda clare linusDiploma In Medical Sciences – January 2. At the end of this laboratory activity, the students should be able to: Be introduced to the principles and terminology of chromatography and demonstrate separation of the dyes in colored pens with paper chromatography. Chromatography Lab Answers Purpose The purpose of the experiment is to determine the specific types of pigments found in a beat leaf and in a spinach leaf by using paper chromatography and two solvents: water soluble solvent and lipid soluble solvent.
Research & analysis report on a practical use for paper chromatography. Chromatography is a major operation used in many different operations in chemistry. Lab 6: Paper Chromatography Pages Pre-lab page No Post lab – Chromatogram must be turned in attached to lab report. Chromatography • Chromatography is an analytical technique used to separate the components of a mixture. • All forms of chromatography work on the.