Gas Chromatography Lab

Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.

Abstract: One mixture of two unknown liquid compounds and one mixture of two unknown solid compounds were separated, isolated, purified, and characterized by boiling point. Two liquid unknowns were separated, isolated, and purified via simple distillation. Then, the process of an acid-base extraction and washing were used to separate two unknown compounds into two crude compounds: an organic acid and a neutral organic compound. Each crude compound was purified by recrystallization, resulting in a carboxylic acid (RCO2H) and a pure organic compound (RZ). The resulting mass of the pure carboxylic acid was 1.688g with a percent recovery of 31.80%, the boiling range was 244-245 °C, and its density was 2.0879g/mL. The resulting mass of the pure organic solid was 2.4902g with a percent recovery of 46.91%, the boiling range was 52.0-53.4°C, and its density was 1.5956 g/mL.

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.

The first TLC plate showed that the fractions collected during the experiment that appeared to be the purest were fractions 4 and 6. These two fractions and fractions number 5 were combined for the final product. The Rf values for the standard carvone, fraction 4, and fraction 6 were all 0.32 indicating that these compounds were

6. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene; to purify the crude product of either trans-stilbene, cis-stilbene, or styrene reaction.

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

Identifying the three components of the unknown mixture, a 1.5 g sample was obtained and dissolved in 30 mL of diethyl ether. This solution was then poured into a separatory funnel with a funnel with the stopcock closed, and inverted twice so that there would be a formation of different layers in the mixture. In order to extract the base from the mixture, approximately 14 mL of 10% hydrochloric acid was added into the funnel and mixed. To mix the hydrochloric acid thoroughly the funnel was gently shaken with the pressure released by removing the stopper intermittently. The solution then separated into an aqueous layer at the bottom, and an organic layer at the top (containing the acid).1 The aqueous layer (containing the base) was released into an

The purpose of this lab is to investigate the processes that can be used to separate two volatile liquids in a mixture based on their chemical properties. This is accomplished by fractional distillation, which separates chemicals in a mixture by differentiating them by their boiling points at atmospheric pressure. Specifically in this lab, fractional distillation is used to separate an unknown mixture into its respective pure components. The components are then identified using gas chromatography, which is also telling of the purity of the extracts and success of the procedure. The procedure of this experiment was specified in lecture by Dr. Fjetland and in Gibert and Martin’s student lab manual, Experimental Organic Chemistry: A Miniscale and Microscale Approach, 6th Edition.

A few crystals of potassium iodide was added to the flask and then swirled to dissolve the solid potassium iodide. The volume of the liquid in the buret was read. The liquid in the buret was titrated with the thiosulfate solution until the brown color of iodine had disappeared. Afterward, 1 mL of starch solution and then thiosulfate solution was added until the blue color of the starch-iodine complex disappeared. The volume of the liquid in the buret was read again. Also, a large test tube was cleaned and dried. 50 mL of iodine solution was carefully measured with a 25 mL graduated cylinder. Next, 5.0 mL of cyclohexane was measured and added to the graduated cylinder. The test tube was stoppered with a rubber stopper. The mixture was shook for one minute at first, then for about five minutes. The process was repeated, where the 50 mL of iodine solution in a 25 mL graduated cylinder was obtained, and then a second 50 mL of iodine solution and 8.0 mL of cyclohexane was added. Next, the cyclohexane layer was removed with a Pasteur pipet from the first test tube into a beaker. In addition, 25.0 mL of the water layer was poured into a clean,

The products of interest within this experiment are 2-methyl-1-butene and 2-methyl-2-butene from sulfuric acid and phosphoric acid catalyzed dehydration of 2-methyl-2-butanol. The reaction mixture was then separated into its separate alkene components by steam distillation and then analyzed by gas chromatography (GC), Infrared Radiation (IR) spectroscopy, and Nuclear Magnetic Resonance (NMR) imaging. Gas chromatography is an analytical technique that is able to characterize if specific compounds exist in a reaction mixture, even if they are in low quantities, assess how much of a compound exists within a reaction mixture relative to other components within the sample, and determine the purity of an isolated product. In the case of this experiment, gas chromatography is used to analyze how pure the alkene reaction sample was and if any remnants of impurities or 2-methyl-2-butanol remained in the sample after isolation of alkene components.

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.

Aim The objective of this experiment was to separate a mixture of two compounds (ferrocene and acetylferrocene) using adsorption column chromatography. Introduction Adsorption column chromatography is a technique that uses a solid stationary phase which is fixed and a liquid mobile phase that moves slowly through the packed column. This technique uses the property of polarity as the compounds have a greater affinity towards the respective phases (either stationary or mobile) which leads the compounds moving at different rates through the packed column and separating from one another.

There are four different kinds of chromatography, there is gas, paper, liquid, and thin-layer. Gas chromatography is mostly used to determine the chemical composition of the unknown substances. Thin-layer is used on thin plastic or glass trays to identify the composition of pigments and chemicals. Liquid is used to identify an unknown plant pigments and other compounds. Lastly, paper can be used to separate the components of inks and dyes. So in this essay i will talk about two real life cases that involve Gas and paper chromatography and

By Using specific methods of compounds detection, we can match an unknown compound with a known compound because similar compounds will display similar characteristics. In this experiment, identifications of the unknown ketone was accomplished using thin layer chromatography, melting point, and NMR spectrometry. Thin layer chromatography is very quick but sensitive way of determining the components of a mixture or a specific compound from a list of knowns. This method is the one which was utilized in the

This Layer Chromatography applications are also involved in forensic studies where it is used to examine fibre dye composition. It is also applied in the examination of pesticides and/or insecticides in food and the isolation or separation of biochemical metabolites or constituent from its body fluids, blood plasma, serum, urine etc.