Essay On Gas Liquid Chromatography

Adsorption chromatography occurs when “one substance form[s] some sort of bonds to the surface of another one”, creating intermolecular forces between the two substances (Chemguide). For thin layer chromatography, the components of the mixture are adsorbed onto the stationary phase that covers the plate (Chemguide). The more polar a substance is, the more strongly adsorbed it is (Chemguide) and the strong intermolecular forces then result in a slower rate of migration with respect to the moving phase. As the solvent touches the TLC plate, the solute (mixture) is allowed to move up the TLC plate

In radical halogenations lab 1-chlorobutane and 5% sodium hypochlorite solution was mixed in a vial and put through tests to give a product that can then be analyzed using gas chromatography. This experiment was performed to show how a radical hydrogenation reaction works with alkanes. Four isomers were attained and then relative reactivity rate was calculated. 1,1-dichlorobutane had 2.5% per Hydrogen; 1,2-dichlorobutane had 10%; 1,3-dichlorobutane had 23%; and 1,4-dichlorobutane had 9.34% per Hydrogen.

Which one of the statements concerning valence bond (VB) and molecular orbital (MO) bond theories is correct?

This experiment was done in order to understand both fractional distillations and gas chromatography. In addition, this experiment was done to separate and identify two liquids that made up an unknown mixture. Gas chromatography was used to figure out the ratio of these two liquids.

Answer: Gas chromatography (GC) – utilized by scientists in order to be able to separate the volatile

This purpose of this lab is to use gas chromatography to identify unknown compounds. In this lab, six known substances were first tested for their retention times to be used as standards when figuring out the three substances contained in a known mixture. The vernier mini gc in this experiment, just like all the other types of chromatography, have both a stationary and mobile phase. With this instrument, the stationary phase is a metal outer column and the mobile phase is the atmospheric air, which is how the vernier mini gc works. This instrument is used alongside a computer to be able to obtain the readings of the injected substances and shown as peaks on a chromatograph. The specific time it takes for a substance to exit the chromatography

In 1941 Martin and Synge, described the discovery of liquid-liquid partition chromatography and also laid the foundation of Gas liquid chromatography and High performance liquid chromatography. They also introduced the concept of the Height Equivalent to the Theoretical Plate, which has since been adopted as the measure of Chromatographic efficiency.

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

Distillation is a method of separating two volatile chemicals on the basis of their differing boiling points. During this lab, students were given 30 mL of an unknown solution containing two colorless chemicals. Because the chemicals may have had a relatively close boiling point, we had to employ a fractional distillation over a simple distillation. By adding a fractionating column between the boiling flask and the condenser, we were able to separate the liquids more efficiently due to the fact that more volatile liquids tend to push towards the top of the fractionating column, thereby leaving the liquid with the lower boiling point towards the bottom. After obtaining the distillates, we utilized a gas chromatograph in order to analyze the volatile substances in the gas phase and determine their composition percentage of the initial solution. Overall, through this lab we were able to enhance our knowledge on the practical utilization of chemical theories, and thus also demonstrated technical fluency involving the equipment.

     In liquid chromatography, the separator is called the column and consists in most cases of a tube filled with porous material called the stationary phase. A liquid, called the mobile phase, flows through the tube between the particles of stationary phase material. A liquid sample is taken from a mixture to be analyzed and introduced to a part of the system that is at elevated pressure. The sample is then transported to a separator by the flow in the system.

During the first run through of the lab, Gas Pressure Sensor is connected to the LabQuest with a small plastic syringe connected to it. The syringe is set 15 mL marker (volume) and the pressure is recorded as 101.19 kPa. By changing the syringe 2 mL down for each run (4 times), the following volume and pressure reads as stated on the data sheet: 13 mL with the pressure of 117.91 kPa, 11 mL with the pressure of 139.25 kPa, 9 mL with the pressure of 165.72 kPa, and 7 mL with the pressure of 216.14 kPa.

High Performance Liquid Chromatography, abbreviated HPLC, is a type of Chromatography that uses liquids to separate mixtures. Unlike other chromatography methods, HPLC uses liquid mixtures for both the mobile and the stationary phases. A syringe is used to inject a small amount of the mixture we’re looking to separate into the HPLC column, and the mobile phase acts as the transporter. The mobile phase contains a carrier liquid that is comprised of all of the dissolved substances that are of interest (the ones that we are looking to separate from one another). Since HPLC uses a reversed-phase stationary phase, this allows polar molecules to elute first and nonpolar last. Therefore, it is imperative to use a polar molecule for the mobile phase

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.

AIM : Thin-Layer Chromatography can show many different characteristics of a mixture. It is recognized for isolation , separation ,identification, and anaylsis of the mixture’s components. The purpose of this experiment is to separate carbohydrates into its pure components such as mixtures of monosacrides by TLC. TLC is used to identify sugars in normal and pancreatic disease urine, the procedure is easy and reproducible .