ipl-logo

Principle Of Chromatography Essay

977 Words4 Pages

The chromatography term is derived from a Greek word Chromo for color and Graphe for writing. Chromatography is a separation technique based on the partitioning behavior. The concept of chromatography was introduced by a Russian botanist Mikhail Tswett in 1906.
In this technique solute of interest is partitioned between two phases i.e. a mobile phase and a stationary phase depending on the partitioning value.
The mobile phase includes the solvent and the stationary phase includes the column in which the solvent is immobilized.
The techniques mainly depend on adsorption, partition, ion exchange or molecular exclusion.
The analyte is in equilibrium between the two phases and the distribution depends on the partitioning coefficient.
Amobile …show more content…

the Height Equivalent to a Theoretical Plate (the smaller HETP narrower the eluted peak).
If the length of the column is L, then the HETP is
HETP = L/N
Where N is the number of theoretical plates
A chromatographic column can have millions of theoretical plates. The width of bands increases as the retention time (volume) increases.

3.2.2. THE RATE THEORY OF CHROMATOGRAPHY
This theory describes the actual process going on inside the chromatographic column with respect to the time taken for the solute to equilibrate between the stationary and mobile phase. The kinetic effect depends upon how much time the mobile phase spends in contact with the stationary phase.
The rate of elution affects the band shape of a chromatographic peak. It is also affected by the different paths available to solute molecules as they travel between particles of stationary phase.
The reason for band broadening was well explained by Van Deemter equation for plate height
HETP = A + B/u + Cu where u is the average velocity of the mobile phase.
A is the eddy diffusion. B is longitudinal

Show More
Related

  • Eastmamol/540 Week 4

    563 Words  | 3 Pages

    This addition aids in controlling the reproducibility and retention. Separation of the mixture via RP-HPLC can be done using continuous gradient or stepwise to move out the sample components. For every separation, the ideal gradient and volume must be

    Read More

  • 6.03 Pre Lab

    993 Words  | 4 Pages

    Question3: Experiment 3 The unknown acid sample was 1 • Monoprotic Acid Trails Initial NaOH solution (mL) final NaOH solution (mL) The volume of NaOH to titrate the acid (mL) Amount of Unknown Acid sample 1 (g) The moles of the Unknown Acid (mol) Molar mass of the Unknown Acid (g/mol) A 3.38 28.31 24.93 0.150 0.0026 57.69 B 0.18 29.32 29.14 0.175 0.0029

    Read More

  • Separation Of Ramonas Lab Results

    867 Words  | 4 Pages

    To separate the Ramos mixture the group first first conducted the dissolve, filter, evaporate method, and prepared the lab for as well. Though for this lab the substance

    Read More

  • M's Vs Skittles Lab Report

    645 Words  | 3 Pages

    A mobile phase is a fluid the solution is dissolved in and a stationary phase is the material the fluid moves through. The mobile phase can also be called the solvent. The two main types of chromatography

    Read More

  • Ap Biology Chapter 2 Study Guide

    1286 Words  | 6 Pages

    Filtering, evaporating, centrifuging, and decanting something will only physically change it. Chromatography is used to separate different parts of a solution so that it can be identified. It can work because different substances have different attractions to things. Distillation can separate substances, such as salt water, as long as it has different boiling points. It can even be used to purify salt water but it is not cost efficient or energy efficient so it is not suitable for everyday use.

    Read More

  • Solute To Dye Synthesis Lab Report

    940 Words  | 4 Pages

    The Rf value describes the strength of the intermolecular bonds between the solute and the solvent. If the molecule had a very high affinity for the stationary phase it would make the Rf smaller, because it does not want to travel as far. The more time that it takes to travel, the larger the mobile phase is. The mobile phase describes how fast the molecule travel in chromatography.

    Read More

  • Red Dye Concentration Experiment

    663 Words  | 3 Pages

    Summary Determining the concentration of a liquid can be a tricky process involving complex procedures if it were not for science’s ability to test a substance’s absorbency through spectrophotometry. The experiment was carried out to discover the concentration of Red Dye #40 in several common soft drinks. The samples of the dye were diluted, and tested using a spectrophotometer. The absorbencies of these samples were then recorded, and a standard line curve with the concentration equation and R2 value was created with these results. Using the absorbencies of the dye samples, the concentrations of the soda samples were determined using the slope equation provided by the graphing software.

    Read More

  • Using Paper Chromatography To Separate Ink Research

    249 Words  | 1 Pages

    Materials: 100 mL plastic beaker blue crayola marker magenta crayola marker whatman filter paper 10mL tap water plastic pitcher of water blue scissors brown school paper towels SAFE-T plastic view-thru ruler 0.5 mechanical pencil clock Using Paper Chromatography to Separate Ink-Lab sheet Method: Using a small plastic pitcher filled with room temperature water, pour 10mL of the water into a small plastic beaker. If the walls of the beaker are wet be sure to dry them with a paper towel. With your scissors cut the Whatman filter paper into two strips, then cut one end of each strip into a point. Measure approximately two centimeters above the tip of the point on one of the pieces of filter paper with a ruler and mark a straight horizontal

    Read More

  • Paper Chromatography Lab Report

    767 Words  | 4 Pages

    For the orange, the distance the band traveled was 39mm and the distance solvent traveled was 39mm and the Rf was calculated at 1mm. For strawberry the distance band traveled 38mm and the distance the solvent traveled was 41mm and the calculated Rf was .927mm. The colors for strawberry, orange and grape Kool-Aid are made with food dye. There is also salt that is found in Kool-Aid that is why when placed in the tubes containing %NaCl, the solvent caused the drops on the strips to travel so far. The results in this were expected.

    Read More

  • Why Should An Acid-Based Titrations Be Carried Out?

    925 Words  | 4 Pages

    Titrations are a technique used within modern industrial laboratories to measure the proportions of chemicals within a solution. It is a simple and useful method and due to its versatility it can be used within many areas and aspects of science industries to either develop or analyse key chemical compounds. Despite the preparation of standard solutions and the carrying out of titrations being the same in modern industrial laboratories, the methods in which they are carried out can differ. Different ways titrations and standard solutions can be carried out?

    Read More

  • Gas Chromatography Lab Report

    1545 Words  | 7 Pages

    Optimum qualitative and quantitative GC analysis of complex mixtures requires: • good resolution, as shown by distinctive and symmetric

    Read More

  • Empirical Formula Lab Report Essay

    1161 Words  | 5 Pages

    After the reaction is finished, the percentage composition of each element in the product can be found and used to calculate the empirical formula, which is the lowest whole number ratio

    Read More

  • Chromatography Informative Speech

    177 Words  | 1 Pages

    What is chromatography? Well I will tell you! it’s a group of lab techniques that scientists use to separate the components of something by passing the substance through several phases. So usually the sample is sort of suck in the liquid or gas state and is separated and based on how it leaks through a liquid or solid. How does paper chromatography work?

    Read More

  • Chromatography Lab Report Discussion

    1458 Words  | 6 Pages

    The stationary phase is the phase that does not move and the mobile phase is the one that does move. The mobile phase moves through the stationary phase picking up the compounds to be tested. As the mobile phase continues to

    Read More

  • Benzoic Acid Lab Report

    767 Words  | 4 Pages

    Introduction Solubility is a chemical property that is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. The resulting solution is called saturated solution. For example when a sample of sodium chloride solution in water is heated the behavior of the reaction is endothermic obstructing exothermic behavior. Another relationship that can be said about solubility is that the solubility of a solid substance increases as the temperature increases. The solubility of solutes is dependent on temperature.

    Read More

More about Principle Of Chromatography Essay

Open Document