Chromatography Of Food Dyes Lab Report

And finally into test tube 3, I pipetted 1.0 ml turnip extract and 4.0 ml of water. The contents of test tube 1 was poured into a spectrometer tube and labeled it “B” for blank. “B” tube was now inserted it into the spectrometer. An adjustment to the control knob was made to zero the absorbance reading on the spectrometer since one cannot continue the experiment if the spectrometer is not zeroed. A combination of two people and a stop watch was now needed to not only record the time of the reaction, but to mix the reagents in a precise and accurate manner. As my partner recorded the time, I quickly poured tube 3 into tube 2. I then poured tube 2 into the experiment spectrometer tube labeled “E” and inserted it into the spectrometer. A partner then recorded the absorbance reading for every 20 seconds for a total of 120 seconds. After the experiment, a brown color in the tube should be observed to indicate the reaction was carried out. Using sterile techniques, any excess liquid left was disposed

7. Tape the strip to a pencil and rest the pencil on top of the jar so that the strip hangs into the jar. The goal is to have the end of the chromatography strip just touching the surface of the solvent solution, with the colored dots above the surface of the liquid. Make sure that the colored spots do not come in direct contact with the liquid in the bottom of the glass.

The three molecules separated because chromatography paper is made of cellulose. Cellulose is polar, therefore ‘like attracts with like’. As the solvent interacts with the paper, it competes for

For part B, 50 mL of an assigned 50 mL pH solution of either 1 M HCl, 1 M NaOH, lemon juice, and 50 mL of household bleach all in separate 250 mL beakers are to be used. For part C, a hot plate or ice are to be used to make the 1.0 mL assigned temperature specific water. This experiment will also use the 1.0 mL of 0.1 Phosphate buffer.

If a sample’s Rf is lower, that means that it remained closer to the stationary phase. In both variations of the experiment, red dye #40 remained the closest to the stationary phase (on average). Therefore, the red dye #40 had the lowest rate of flow value. The intermolecular forces of the red dye are responsible for its low distance traveled. The molecules of the chromatography paper have strong intermolecular bonds that are highly polar. The red dye is attracted to the paper because of their similar characteristics. The negative and positive ends of both the paper molecules and the red dye #40 molecules attract to each other. It is extremely difficult for the isopropyl alcohol and the sodium chloride solutions to interfere with the bonds of paper and ready dye #40, as a result, both solutions are unable to fully dissolve red dye #40. . NaCl and isopropyl alcohol have very strong intermolecular forces, but the forces of the paper’s molecule were able to attract red dye #40 because they were even

If you put too much of a sample on your chromatography paper, you could possibly have that color bleed into the color next to it, which would mess up your results. If you put too little of a sample on the paper, your color

(a) (3 pts.) This video discusses 3 different types of chromatography. List each one mentioned, and describe their differences in as much detail as possible (your points earned will be proportional to the level of detail in your discussion). Which one was used in this lab demonstration?

In the first part, there may have been cross contamination of materials, especially since periods before us had already performed the experiment. During chromatography, our spot sizes were initially very varied, as we didn’t know exactly how much of each substance to place when we began. Thus, the substances in more abundance would have greater opportunity to travel up with the eluent, skewing the results. In the beginning, we even put 6-7 drops, causing some of the substances to mix together. Touching the TLC plate may also have disrupted some of the substances traveling up.

Using the yellow tube, which included everything but starch, as the blank, each group zeroed their spectrophotometer. This was done so that any absorbance observed depends only on the amount of starch present, not on any other reagents (buffer, IKI). To zero the spectrophotometer, the wavelength was first set at 580nm, using knob 3 (45). Next, the groups made sure that the light next to “transmittance” was lit, and the chamber to be tightly closed. Having the chamber empty & closed tightly provides reference for the darkest condition possible. Using knob 1, the transmittance was turned until it read 0.0 (45). Before the groups used their blank test tube to zero the spectrophotometer, each needed to wipe the tube with kimwipes to ensure a clean reading. Turning knob 2, each group was then instructed to zero the absorbance, 0.000. Upon removing the blank, each trial was inserted into the chamber (46). The

1. Paper Chromatography is a method used for the separation of colors which are also referred to as colored chemicals/substances or pigments. This method is used for experiments, to identify coloring agents and to separate out a compound into its various components.

Thin Layer Chromatography (TLC) works in relation to the polarity of chemicals. A plate is first covered with aluminum foil or silica etc. and has solutions of varying polarities placed upon the aluminum foil or silica. When placed in a in a puddle of solvent that moves up the plate, the different inks i.e. the solution will move up the place based on their Rf values. Adherence increases with increasing polarity, so the less polar compounds will be carried farther by the solvent. Eventually the dyes will separate into their compontnets, which can be visibly seen. This is then used to determine who the ink of the unsigned note belonged to along with the pen that it belonged

Chromatography is a fairly simple process. First, you put a dot of ink(or in our case, the M&M food dye) near the bottom of some chromotography paper (also known as filter paper), and then hang the paper vertically with its lower edge (the one closest to the spot of dye) dipped in a solvent (In our case, the sodium chloride solution). Capillary action forces the solvent to travel up the paper, where it meets and dissolves the ink. The dissolved ink (which is the mobile phase) slowly travels up the paper (the stationary phase) and separates out into its different elements. Another way of describing it is to think of the liquid as an adhesive-like liquids, some of which stick more to the solid and can travel more slowly than others. This is

The first part of this experiment uses thin layer chromatography (TLC) while the second part involves column chromatography

Measure the heights listed in the chart using a meter stick positioned with one end on the splatter paper and the other end measuring dropper height.

The following procedure dealt with a chromatogram. The materials needed are: a pencil, safety goggles, scissors, chromatography paper strip, capillary tube, spinach plant pigment extract, test tube, cork stopper, graduated cylinder, chromatography solvent (alternative isopropyl alcohol), metric ruler, stopwatch or clock with a secondhand, hook/fashioned paperclip, paper towels, test tube rack, and mortar and pestle. First we obtained a strip of chromatography paper and cut it so it would fit inside a test tube (with it barely touching the bottom of the tube). Also, when touching the strip, touch the sides only. Then we attached (firmly) the top of the strip to a hook (or fashioned paperclip at bottom of the cork stopper). Make sure it fits in the test tube. Next we used the pencil to draw a faint line across the strip two centimeters from the bottom tip of the strip. We placed the cork and strip in place, and we put a mark on the test tube one centimeter below the top of the stopper.