Cell Phase And Stationary Phase

Background: Paper chromatography is one method for testing the purity of compounds and identifying substances. Paper chromatography is a useful technique because it is relatively quick and requires small quantities of material.

The most polar molecules on a chromatography strip move the least, and the least polar molecules move the most. Out of red dye #40, blue dye #1 and yellow dye #5, the molecules in blue dye #1 have the polarity closest to both isopropyl alcohol, and sodium chloride solutions. Red dye #40 has the most polar molecules, while blue dye #1 has the least polar molecules.

The similarities between column and paper chromatography is that both have a stationary and mobile phase. The stationary phase in the paper chromatography is the paper, and in the column is the sodium bicarbonate. The mobile phase in the paper chromatography is the movement of the solvent, .3% NaCl, and the column is the different solutions added. Column chromatography is basically the same as paper chromatography, except that the dye solution would have to be added individually rather than being able to do it all at once, like it does when using chromatography

Answer: Once the chromatogram has been completed and is ready to be measured and calculated, on the plate that was used to perform the chromatogram you should see where the red and blue have completely separated. The red food coloring dye should be lower on the plate than the blue food coloring dye.

2. Which pen matches the unknown ink? Provide a clear list of arguments as to why you believe it is a match.

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

We put these test tubes in an ice bath with salt and measured the temperature with thermometers. Unfortunately we ran out of time, and inferred that we had chilled the ink to the coldest temperature we could create. We found that both of the inks had a freezing point of less than 7 degrees fahrenheit. In addition, we used paper chromatography to determine the identity of the substance. The results were that both strips of paper had the same colors on it, but our ink appeared more linear and the ink from the lab appeared more mixed or tie-dyed.

In thin layer chromatography a stationary phase, silica gel with a glass backing, is dotted on a pencil drawn

The first of these three methods is microscopy, used most notably by Walter C. McCrone. As defined by McCrone, microscopy is “the use of any tool or technique that allows us to identify microscopic objects.” This includes the use of the light microscope as well as more advanced types of microscopes such as the electron microscope and x-ray diffraction (McCrone 1976, p. 676 A). McCrone's methods using microscopy were desirable because they allow observations to be made on small samples so that no visible damage is done to the item being tested. When testing the Vinland Map, McCrone used a small needle with rubber cement on the tip to pick up ink particles. Particles were then observed, first using an optical stereo microscope, and then observed more closely with a series of more advanced microscopic techniques such as the electron microscope and x-ray diffraction (McCrone 1976).

The three solvents in the experiment are one hundred percent acetone, one hundred percent isopropyl, and distilled water. Acetone is nail polish remover and isopropyl is rubbing alcohol. In the experiment, it required distilled water because it is purified and is always the same substance in the container.

Chromatography is a separation technique in which the mixture to be separated is dissolved in a solvent and the resulting solution, often called the mobile phase, is then passed through or over another material, the stationary phase. The separation of the original mixture depends on how strongly each component is attracted to the stationary phase. Substances that are attracted strongly to the stationary phase will be retarded and not move alone with the mobile phase. Weakly attracted substances will move more rapidly with the mobile phase.

Litmus paper will be used to test the eluent repeatedly until it is neutral to blue litmus paper. By elution with acidified methanol, the pure dye solution will be desorbed from the column. A rotary evaporator will then be used again to expel any excess solvent. 3.3 Characterization of dye extracts in terms of chemical structure,

Some pigments move further than others because of the size of their particles. Smaller, lighter particles will move through the filter paper more swiftly than larger, heavier particles. This is true because smaller, lighter particles are more soluble in solvent, thus allowing them to move further. In addition, a pigments affinity for paper will affect its distance travelled. The more polar a substance is, the greater attractiveness it will have to paper through hydrogen bonding (Jeffrey & Saenger 149). Therefore, the pigments particle size, solubility, and attractiveness to paper will determine the distance it moves.

Aim-To investigates the effect of changing the polarity of mobile phase on Retention time (RT) and Column capacity (k’).

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.