Lab 2A: Chromatography Lab by Katie and Nick

Chromatograph #1 After the water

Chromatograph #1 before the water   

                                         

Chromatograph #2
Chromatograph #1

1. Why is it important that only the wick and not the filter paper circle being contact with the water in the cup?

The ink from the marker is being carried through the filter paper gradually by the water. This way we can see which substances are quickly absorbed into the paper and which ones can travel farther up the paper with the water. If the paper were fully submerged in the water, we would not be able to see the differences in distance travelled by different substances.

2. What are some of the variable that will affect the pattern of colors produced on the filter paper?

The distance from the center affected what kind of design appeared on the paper. We also learned that drawing various shapes and lines on the paper will change the design. The ink from different markers produced different colors. Somer were very colorful, others were just blue or black. Leaving the paper on the wick will allow the water to dilute the color more. For example, the bottom design was left in the water longer than the top design.

3. Why does each ink separate into different pigment bands?

Depending on what substance makes up the ink, some inks are easily absorbed into paper while others can flow through it easily like the water. From our observations, orange and yellow stay close to the middle because it stays printed on the paper. However, pink can travel farther than that and light blue is always out on the very edge.

4. Choose one color that is present in more than one type of ink. Is the pigment that gives this color always the same? Do any of the pens appear to contain a common pigment?

Light blue was a color used in many of the inks. Repeatedly light blue was the one that always spread out the furthest. The similarities between the chromatograms shows that different pens appear to use same pigments.

5.  Why are only water-soluble markers or pens used in this activity? How could the experiment be modified to separate the pigments in "permanent" markers?

Water soluble markers can be broken down when the water passes through the ink. Therefore, it is easier to see the separation of the pigments when they spread out on the adsorbent along with the water. Using a solvent that can break down the different pigments in the ink of a permanent marker will allow us to create a chromatograph using a permanent marker.