2: Paper Chromatography of Gel Ink Pens (Experiment) - Chemistry LibreTexts

 

ink chromatography lab report

Forensics: Ink Chromatography Lab Background: Chromatography is a method for analyzing mixtures by separating them into the chemicals from which they are made. It can be used to separate mixtures like ink, blood, gasoline, and lipstick. Ink Chromatography Lab Chromatography is a method of separating out materials from a mixture. Ink is a mixture of several dyes and therefore we can separate those colors from one another using chromatography. When ink is exposed to certain solvents the colors dissolve and can be seperated out. Apr 21,  · Paper Chromatography Introduction The purpose of this experiment is to observe how chromatography can be used to separate mixtures of chemical substances. Chromatography serves mainly as a tool for the examination and separation of mixtures of chemical substances. Chromatography is using a flow of solvent or gas to cause the components .



Chromatography is a method of physically separating mixtures into its individual components. It is a common laboratory technique used to identify unknown components in mixtures. There ink chromatography lab report several types of chromatography; all types employ a mobile phase or eluent it can be liquid or gaswhich is forced through a stationary phase a solid or semi-solid, ink chromatography lab report.

Mixtures are separated because some components will be more attracted to the stationary phase and stick to it while some components will be more attracted to the mobile phase and travel with it.

By eye, we cannot know if each ink color is a mixture or pure substance. Using chromatography, the components in a sample will migrate along the filter paper at different rates such that they become spread out and separated from each other. The mobile phase takes advantage of differing solubility or polarity of the components in order to separate them. This component traveling process is called elution. Chromatography can be used to separate inks, dyes, pigments in plants, ink chromatography lab report, or used to determine the chemical composition of many substances.

Figure 1 shows a beaker containing mobile phase and a prepared paper stationary phase. A line drawn ink chromatography lab report the bottom edge of the paper is the starting line. The starting line and ink dots must be above the level of the mobile phase when the paper is placed inside the beaker.

If the starting line is below the liquid level, the inks will wash out into the ink chromatography lab report phase rather than elute up the stationary phase. Another line is drawn about 10 cm above the bottom edge of the paper. This is the finish line. Its location was chosen for this experiment because when the eluting solution reaches that line, ink chromatography lab report, any inks that are mixtures should be clearly separated.

When the solvent front reaches the finish line, the paper should be removed immediately from contact with the mobile phase. Figure 2 shows a typical paper chromatogram. There are a few difficulties commonly encountered in the elution process. One problem is that spots tend the spread out as they elute, and can bleed into each other as they proceed up the paper.

This can be confusing when interpreting the chromatogram. To avoid this problem, space the spots of sample far apart and make repeated, tiny applications of sample to prevent spreading. Another problem is an uneven solvent front.

This can happen if the beaker is nudged — if the mobile phase sloshes inside, the elution trails may travel diagonally, which makes interpretation very difficult. This can also happen if the two edges of the chromatogram are allowed to touch when they are stapled or taped together to form a cylinder. A component with a given solubility travels along with the mobile phase at one rate, regardless of what other components are present in the sample.

If the red part of purple ink travels at the same rate as pure red ink, and both stop in the same place, the two should be the same red ink.

The two red spots should have the same Retention FactorR f. Comparing the R f values allows the confirmation of a component in multiple samples because unique components have unique R f values. Wear safety goggles at all times. Use eluting solution only in the hood. Do not breathe fumes from the eluting solution. Be sure to handle only the dry part or the chromatogram when removing it from the beaker. Wash hands thoroughly if the eluting solution touches your skin. Personal protective equipment PPE required: lab coat, safety goggles, closed-toe shoes, gloves.

Draw an X through any unused boxes. Objectives To use paper chromatography to identify whether certain colored inks are pure substances or mixtures. To obtain a paper chromatogram of various gel inks To identify components of inks by calculating R f values. Note When the solvent front reaches the finish line, the paper should be removed immediately from contact with the mobile phase.

Procedure Materials and Equipment Materials: chromatography paper, gel pens, and eluting solution. Equipment: mL beaker, ink chromatography lab report, pencil, ruler, plastic wrap, tape and paper towels.

Safety Wear safety goggles at all times. Part A: Preparation of Chromatography Paper Wash your hands thoroughly to remove excess oils from your skin. Obtain a ruler and a piece of chromatography paper from your instructor. Handle the paper only on the edges to avoid leaving fingerprints, as these may hinder the elution process.

Place the chromatography paper on a sheet of clean ink chromatography lab report paper or paper towel to avoid picking up dirt or contaminants from the bench top, ink chromatography lab report.

Using a pencil and ruler to measure accurately, draw a straight line across the paper, about 1. This is the starting line. Draw another line about 10 cm above the bottom edge. On the starting line, measure in from one side about 2. Draw seven more, 1. In the center of each X, make a small spot of ink color in this order: black, burgundy, red, pink, violet, ink chromatography lab report, green, ink chromatography lab report, blue When you have finished, you should have something that looks like Figure 3.

Figure 3: Prepared Chromatography Paper Go back over each ink spot a second time to ensure there is enough ink in the spot. Obtain a small piece of tape and gently curl the paper into a cylinder, with the spots on the outside, ink chromatography lab report. Tape the ends together near the top and bottom, taking care that the two edges of the paper do not touch.

If they do touch, the eluent will creep on a diagonal, and the spots will run together, or not in straight lines. Obtain a piece of plastic wrap to cover the top. Ink chromatography lab report place the paper cylinder into the beaker and cover the top with the plastic wrap.

Remember that the spots must be above the liquid level for the experiment to work. Watch the eluent creep up the paper until it begins to move some of the ink. It will take about minutes for the solvent front to reach the finish line. When the solvent front reaches the finish line, remove the paper from the beaker, being careful to touch only the top.

Let excess eluent drip into the beaker. Gently remove the tape and lay the chromatogram on a piece of paper towel in the hood. Leave the paper in the fume hood, where it will dry completely. If needed, use a heat lamp in the fume hood to dry the chromatogram; if using the heat lamp, allow minutes to dry. Circle around each color spot. Use a ruler and draw a plus sign in the center of each spot.

Measure the distance from the starting line to each plus sign. Record this distance for each spot on your lab report. Measure the distance between the starting line and the finish line or, the farthest up that the solvent front reached. Record this distance. Calculate the retention factor R f for each spot and record the values in your lab report.

You and your lab partner will hand in your lab reports at the same time, with the paper chromatogram stapled to the lab reports. What other ink chromatography lab report can we use chromatography for? Are any of the R f values in the table above the same or similar, within 0. What would the same or similar R f values indicate? What are the units for R f values?

Record ink colors in the appropriate column; for mixtures, list the colors of the components. To the stationary phase? Which of the materials tested gel ink pen and colored markers had an R f value of zero? The air we breathe is a mixture of different components.

What is the composition of dry air, ink chromatography lab report, by percentage? See Fig 1.

 

 

ink chromatography lab report

 

Lab Report: Paper Chromatography of Gel Ink Pens. Part C: Interpretation of Chromatogram; Record this distance for each spot on your lab report. These are the \(D\) values, in cm. Measure the distance between the starting line and the finish line or, the farthest . Paper Chromatography Lab 7. If the ink you are testing does not spread out, re-test it using pure rubbing alcohol. (This means that the ink is not water soluble) 8. When the solvent reaches the top, quickly remove the strip(s) of paper and mark WITH PENCIL the solvent front and the position of each color dye. (If your dye is a pure substance. to separate mixtures like ink, blood, gasoline, and lipstick. In ink chromatography, you are separating the colored pigments that make up the color of the pen. Even though a pen will only write in one color, the ink is actually made from a mixture of different colored pigments. To perform ink chromatography, you put a small dot of ink to be.