Paper Chromatography Lab Report

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.

Three paper towels A, B, and C where tested on absorbency. This experiment was tested twice. Paper towel A was 26.5 by 28 centimeters. Paper towel B was 26.5 by 28 centimeters. Paper towel C was 15 by 28 centimeters. Scissors were obtained and each paper towel was cut to 13.5 by 15 centimeters. The weight of the three paper towels at this size was 0.9 grams dry for paper towel A, paper towel B weighed 0.8 grams dry, and paper towel C weighed 1.2 grams. Three beakers weighing 12.2 grams each were obtained. Each beaker was filled with 100ml of water with the outcome of them weighing 128.1 grams each. The weight of each paper towel dry was deducted from the weight of each paper towel. Paper towel A was left to soak for seven seconds.

Introduction A mixture is a combination of two or more pure substances that are physically combined [not chemically combined]. There are two types of mixtures, which are homogeneous mixtures and heterogeneous mixtures. Homogeneous mixtures are mixtures that have components which are uniformly distributed throughout the mixture. For example, sugar water is a homogeneous mixture.

The purpose of this lab is to separate a mixture and determine the percentages of each of the ingredients. Each substance will have a different boiling point due to its intrinsic properties and from that, we will be able to determine the purity of different products as we evaporate off the next level of product.

The stationary phase will absorb or slow down different components of the tested solution to different degrees creating layers as the components of the solution are separated. Chromatography was invented by the Russian botanist, Mikhail Tsvet. Chemists use this process to identify unknown substances by separating them into the different molecules that make them up.

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.

The investigation is showing how enzymes work inside a mammal's stomach. Rennin is the enzyme found in young mammals and has more effect

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

Once these steps were completed, the cuvette was placed into the spectrophotometer to test for phosphate, nitrate, ammonia, and turbidity. Inside the spectrophotometer, a light was shot through the sample to detect the contaminant. The first ever spectrophotometer was only developed to calculate pH levels and never used wavelength to calculate the abundance of chemicals within a sample. After many years of developing the spectrophotometer, a glass prism was installed. This allowed the spectrophotometer to use light wavelength to calculate the concentration of chemicals within a sample. The light was able to read the preferred contaminant because a reagent attached to each molecule, and the light was reflected back instead of being shot through the sample. This gave the concentration of each contaminant in the sample. In each machine, there was a different light wavelength programmed to shine through the sample to detect the different contaminants. This was done to get an accurate measurement of phosphate, nitrate, and ammonia within the sample. Turbidity was also measured using the spectrophotometer, but there was no reagent added. The turbidity was calculated by testing distilled water first and comparing it to the turbidity of the BSR water.

The objective of this lab was to separate a mixture that consisted of elements and compounds. There are seven ways to separate a mixture which included paper chromatography, filtration, evaporation, simple distillation, fractional distillation, magnetism, and separating funnel. The only methods used in this lab were filtration, evaporation, magnetism, and separating funnel. The method of magnetism was used when the magnet was moved under the mixture to separate the iron. The process of filtration involved the use of a filter paper placed in a filter funnel. The funnel was placed in a beaker and the mixture of water, sand, and sodium chloride was poured into the funnel. The liquid part drained through the filter paper into the beaker, leaving the solid sand particles trapped on the filter. After the water and sodium chloride were in a beaker, the process of evaporation was used. The compound was boiled on a hot plate, which led to the water

The Thin Layer Chromatography of Drugs lab taught me how chromatography could be used to identify the compounds of an unknown drug. This procedure relied on using compounds that had a known travel distance, which served as the control, and examining how far the compounds in the unknown drug traveled. The results of this experiment indicated that drugs are chemical molecules with a diverse amount of compounds i.e.: caffeine, acetaminophen, asprin, etc. The essentials of this lab relied on two factors that allow for the separation of different compounds from the drug.

Pigments extracted from different greens have different polarities and may be different colors. Mixed pigments can be separated using chromatography paper. Chromatography paper is able to separate mixed pigments due to their polarity and solubility. Pigments of chlorophyll a, chlorophyll b and beta carotene will be separated on chromatography paper because each has its own polarity and solubility, which results in different distance traveled up the paper. Beta carotene is non-polar so it travels the highest distance, followed by chlorophyll a. Chlorophyll b is the most polar; therefore, it travels the shortest distance. The separated pigments on the chromatography paper can be eluted in acetone and absorbance spectrum is

     After the column the separated compounds enter the detector, which measures a physical or chemical property of each, now relatively pure, compound and creates a proportional electronic signal. By calibrating with a standard mixture of known compounds, the nature of the compound in the

Chromatography Investigation Chromatography is a highly regarded technique used to separate the components of a mixture. It is based on the principle that each component possesses a unique affinity for a stationary phase and a mobile phase. The components that are more inclined to enter the mobile phase will migrate further on the chromatogram and distinguish themselves from the other components. The type of solvent used in chromatography is known to directly affect the separation of the mixture. In this experiment, thin-layer and column chromatography will be utilized to separate the numerous chlorophyll and carotenoid pigments of a spinach extract.

Gel-Filtration Chromatography is a commonly used method used in order purify a protein from a mixture, by means of separations. Different biomolecules differ in size, or their molecular weight. In the gel matrix inside the chromatography column, there are gel beads which are porous to allow certain sized molecules to enter. The molecules that are able to enter the pores of the gel, are held in stationary phase and will elute from the column later on, these are usually smaller, to medium sized molecules. Larger molecules that are not able to fit in the pores will elute out of the column first, they are involved in mobile phase where they just go straight through the column without interacting with the gel beads. Smaller molecules will have a higher elution volume, while the larger molecules will have a lower elution volume. The volume to elute the protein is inversely proportional to the molecules size.