Introduction Of Gas Chromatography, Ethyl Benzene, And O Xylene

Different procedures were used to isolate benzil from the ether layer and benzoic acid from the aqueous layers. To isolate benzil, anhydrous MgSO4 was added to the flask containing the ether layer solution. MgSO4 removes the remaining water in the ether layer solution. After making sure that enough amount of MgSO4 present in the solution, the ether solution was filtered by using gravity filtration. During filtration, MgSO4 was removed from the solution and the ether solution was collected in 25 ml flask. To separate benzil from the filtered ether solution, the beaker containing the ether solution was heated until the ether evaporated. After letting the beaker to cool to room temperature, the mass of the beaker with the benzil crystals was measured. From the combined mass of the beaker and the benzil crystals and from the predetermined mass of the beaker, the mass of the collected crystals was calculated to be 0.266 gram.

Introduction: The fundamental techniques of organic chemistry lab, commonly known as SIPCAn, include separation, isolation, purification, characterization, and analysis (1). Through SIPCAn, students learn the fundamental techniques of organic chemistry laboratory. Mastering these techniques are necessary in order to perform more complicated experiments and to carry out organic reactions and synthesis. The information gained from SIPCAn included boiling point, melting point, and density can be used to identify unknown compounds. Simple distillation was used to purify a compound by separating it from a

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

On a thin chromatography plate, five spots were placed ( as shown in table 2) and the plate was developed using chloroform/methanol. This was later visualized with dragendorff’s reagent under the UV light. All separated components were observed, identified and recorded.

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.

A measurement of around 0.5 µL, for each compound, was inserted into a gas chromatography in such a way, a syringe holding the compound was pushed down into a column and injection occurred to then start the machine in separating the compound. A computer was right beside it, indicating the graph of multiple peaks and later, after a duration of 4 minutes, a graph was printed out and obtained to then analyze the retention times and percent composition. “The percent composition was found by inserting the following values into the following equation,

The compound being tested is placed as a liquid into the gas chromatogram and it is vaporized. The mobile phase is a gas, and the vaporized sample is pushed through a coiled column by a carrier gas, which is chosen so that it is unreactive with the sample. The coiled column is also coated by a liquid which serves as the stationary phase. The different components will reach the detector of the chromatograph at different points, depending on their boiling points. Substances with lower boiling points will vaporize faster, and will therefore reach the detector faster than their higher boiling point counterparts.

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.

The GC-MS is a chromatographic separation technique that is commonly used for the separation and identification of volatile compounds [McMaster 2011]. It merges the features of gas chromatography (GC) and mass spectrometry (MS) to separate using chromatography and identify using mass spectroscopy different substances in a heterogeneous sample. This instruments is suitable for a wide range of applications in the forensic sciences including fire and arson investigation, drug analysis, environmental analysis,

Chromatography is the term used to describe all the separation methods based on the distribution of compounds between two separate phases. TLC, an abbreviation for thin layer chromatography, is a chromatographic technique which is used to separate components of a mixture using a thin stationary which has an inert backing, this occurs as one phase is fixed on a plate (stationary phase) and the other phase is mobile and migrates through the stationary phase (mobile phase). During the chromatographic development process, the mixture to be separated is distributed between the stationary and mobile phases. (Spangenberg Bernd et al 2011). It is mostly used because of its simplicity, relatively low cost, high sensitivity and relatively fast speed of separation. TLC also functions on the same principle as all other chromatography techniques. A compound has different affinities for the mobile and stationary phases, and this affects the speed at which it migrates. The goal of TLC is to obtain well defined, well separated spots. (O. H. Lowry, 1951). In contrast to HPLC, many samples can be run at the same time on TLC. (Journal of Chromatography, vol 19 (2011)).

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

Gas chromatography is a method that separates the components of a solution and measuring the relative quantities. The useful technique of gas chromatography is for chemicals that do not decompose at high temperatures and when a very small quantity of sample (micrograms) is available. Gas chromatography uses are limited as the decomposition temperature of components within a mixture and the composition of the column; columns cannot withstand temperatures that are above 250-350 ¬oC.

approximation of the flavor composition as defined by breath-bybreath measurements and shows higher odorant concentration and

Petroleum analysis makes special use of columns for gas chromatography, with industries expecting continues development of columns for high analytical performances and efficiency.

(1975). HPLC uses either a solid or liquid-coated solid stationary phase and a liquid mobile phase. Separation of analytes is achieved by adsorption of the analyte to the stationary phase. HPLC provides speed, resolution, high sensitivity and specificity (Lima, 2002).