Chemistry: Gas Liquid Chromatography Essay

1360 words - 5 pages

Extraction
To obtain oils from plant materials steam distillation is typically used. Solvent extraction is also used to create a resinoid (resembling characteristics of resin). Solvent extraction is commonly used with volatile substances that may be lost with distillation. Solvent used are pentane, hexane, and mixes of solvents such as ethyl acetate and hexane which is commonly used in place of benzene (see Figure 2).
Gas-Liquid Chromatography
Gas-Liquid Chromatography is the process of separating complex mixtures into the components and measuring the individual components. By using injectors, columns, and detectors researchers are able to enhance the separation and identification of the components.
Headspace Collection
The volatile compounds of a fragrance can be found in the headspace, the air above and around a fragrant substance. This technique is mainly used when trying to collect the fragrance from flowers. Absorbent traps are used to collect the volatiles. Traps are small glass tubes containing activated charcoal. The air is ran through the tubes where the volatiles are collected from the flower which is enclosed inside a bell jar in order to prevent the volatiles from being taken away by the air. Once the traps are removed the traps must be kept cool and dark because of the reactive glass and absorbent surfaces that can cause materials to be ruined (Sells, 2006, p. 225).
Chemical Synthesis
The need for several flavors and fragrances exceeds the amount that is made naturally. The annual amount of vanillin used is 12,000 tons however only 1,800 tons of natural vanillin is produced (Crasto, 2012). Therefore, the extra amount needed is produced through chemical synthesis. The most recent and popular form is a two-step process in which guaiacol reacts with glyoxylic acid by electrophilic aromatic substitution. Electrophilic aromatic substitution is an organic reaction where an atom that is attached to an aromatic is replaced by an electrophile. An electrophile is a reagent that is attracted to an electron that is in a chemical reaction by accepting an electron pair in order to bond to a nucleophile (donates electron pair to electrophile). From this reaction vanillylmandelic acid is formed and turned by 4-hydroxy-3-methoxyphenylglyoxylic acid to vanillin by oxidative decarboxylation. During oxidative decarboxylation a carboxyl group (COOH) is removed forming carbon dioxide.
Perfume Ingredients from Benzene
Benzene
2-phenylethanol is one of the most important ingredients made from benzene. It is part of rose oil and is widely used for its blending qualities. A way to create 2-phenylethanol is to hydrogenate styrene oxide. The production of styrene from benzene produces a good product and the intermediate, styrene oxide, can be used in other materials. By rearranging the epoxide (three atom cyclic ether) phenylacetaldehyde is produced, with a green note. By adding alcohols to styrene oxide the acetals (functional groups) of...

Find Another Essay On Chemistry: Gas-Liquid Chromatography

Importance of Chemical Analysis in day to day life

1398 words - 6 pages chromatography, a liquid sample flows down a vertical strip of adsorbent paper, on which the components are deposited in specific locations. Another technique, known as gas-liquid chromatography (gas-solid chromatography is a more rarely used variant), permits separation of mixtures of gas compounds or substances that can be vaporized by heat. The vaporized mixture is forced by an inert gas along a narrow, coiled tube packed with a material through which the

determination DXM Essay

1499 words - 6 pages , and rapid method for determination of DXM has been become an important target in control pharmaceutical dosage form. Therefore wide range of analytical methods for quantitation of DXM have been developed such as, high performance liquid Chromatography(HPLC) (Abdel-Moety, Al-Deeb, and Khattab 1995, Tedesco et al. 2013, Eichhold et al. 1997, Hoskins, Shenfield, and Gross 1997) (Abdel-Moety, Al-Deeb, and Khattab 1995, Tedesco et al. 2013, Eichhold et

chemistry

1694 words - 7 pages described. In this project, selected gas chromatography-mass spectrometry (GC-MS) and Liquid Chromatography- Tandem Mass Spectrometry (LC-MS/MS) spectra of diazepam (MS lab, Prof M. Abdel-Hamid) for confirmation and quantitation of diazepam are presented. 1. Introduction: BZD are a group of chemically synthetic compounds that were firstly synthesized in late fifties. BZD share a common chemical structure features and their importance comes

GENERAL INTRODUCION

962 words - 4 pages Spectrophotometry and Nephelometry or Turbidometry), Electrochemical (Potentiometry, Amperometry and Polarography) and Chromatography (Paper, Column, Thin Layer6, Gas Liquid7, High Performance Liquid8,9) methods are usually preferable. Methods involving nuclear reaction such as Nuclear Magnetic Resonance (NMR) becoming more popular. The combination of GC-MS is one of the prominent powerful tools available. The chemical methods include the

The Mechanics Of The Drinking Bird

1212 words - 5 pages the felt is and what the inner liquid is. The first question is the easier of the two to answer, the felt is meant to hold water to the upper bulb. The beak of the bird is supposes to draw the water up the outside much like chromatography paper would. Even though it is supposed to contain the water, felt is used because water evaporates and cools down the inner vapors, and condenses them back in to the liquid that they were. The second question

Benzodiazepan Screening Process

1858 words - 7 pages . Retrieved from http://www.medscape.com/viewarticle/819562_print 10. Subhra, H., Devasish, B., Josep, E., &Abhilasha, D. (2012). Micellar liquid chromatography for the determination of some less prescribed benzodiazepines. E-Journal of chemistry, 9(1), 443-450. 11. Katzung, B. (2001). Basic & clinical pharmacology. (8th ed., pp. 364-379). San Francisco, SF: McGraw-Hill. 12. Jickells, S., & Negrusz, A. (2008). Clarke's analytical forensic toxicology

Chromatography

668 words - 3 pages alone with the mobile phase. Weakly attracted substances will move more rapidly with the mobile phase.      Liquid chromatography is an analytical technique that is useful for separating ions or molecules that are dissolved in a liquid phase. If the sample solution is in contact with a second solid or liquid phase, the different solutes will interact with the other phase to differing degrees due to differences in adsorption

chemistry

2437 words - 10 pages /content.aspx? bookid=348&sectionid=40381658&Resultclick=2 9. Wilner, A. (2014). Clobazam rash: New warning for an old drug. Retrieved from http://www.medscape.com/viewarticle/819562_print 10. Subhra, H., Devasish, B., Josep, E., & Abhilasha, D. (2012). Micellar liquid chromatography for the determination of some less prescribed benzodiazepines. E-Journal of chemistry,9(1), 443-450. 11. Jickells, S., &Negrusz, A. (2008). Clarke's analytical forensic

What is Ion Chromatography?

2120 words - 9 pages The term chromatography refers to different methods of molecular separation between a mobile phase and a stationary phase based on various physio-chemical properties. There are many types of chromatography that are used as analytical tools in environmental science, forensics, metallurgy, biology, etc. Some common examples are thin layer chromatography (TLC), gas chromatography (GC), high performance liquid chromatography (HPLC) and ion

Distillation of Mixtures Formal Report

1880 words - 8 pages IntroductionThe purpose of this experiment is split up into three parts: separating cyclohexane and toluene through distillation, performing gas chromatography on the substances that were distilled, and separating a salt-water mixture through distillation. Distillation involves the ideas of vaporization and condensation. Through these procedures, liquid mixtures can be purified. An important step in the process is finding a boiling point. When

Effect of Extraction Methods and Solvents Used on Dates' Extraction Yields

2431 words - 10 pages fruits of five UAE cultivars at different stages of maturity. Arab Gulf Journal of Scientific Research, 13, 553–569. Bartolozzi,F., Bertazza,G., Bassi ,D.,& Cristoferi,G.,(1997). Simultaneous determination of soluble sugars and organic acids as their trimethylsilyl derivatives in apricot fruits by gas-liquid chromatography .choromatography A, 758, 99-107. Biglari, F., AlKarkhi, A. F. M., & Easa, A. M. (2008). Antioxidant activity and

Similar Essays

Chromatography Essay

756 words - 4 pages process was discoverd in 1901 by Mikhail Semenovich Tsvett a russian botanist, he was working on a method of separating a mixture of plant pigments. Chromatography is mostly composed by a stationary phase, usually a solid material such as chromatography paper, and a mobile phase, which is the mixture that is being separated and that is most of the cases a gas or a liquid. This separation occurs due to the various components of the mixture that spread

A Thorough Description Of Chromatography Essay

2524 words - 10 pages chromatogram correspond to different components of the separated mixture* A chromatograph takes a chemical mixture carried by liquid or gas and separates it into its component parts as a result of differential distributions of the solutes as they flow around or over the stationary phase* The mobile phase is the analyte and solvent mixture which travels through the stationary phase* Preparative chromatography is used to purify larger quantities of a

Lc Ms And Lc Ms/Ms: Principles And Applications

1470 words - 6 pages chromatography-mass spectrometry: An introduction. John Wiley & Sons, Ltd. 2-3p  DU, Y., YANG, Y. & XU, W.D. 2010. Liquid chromatography combined with tandem-mass spectrometry for multiresidue determination of sulfonamides. RSC publishing. 30:471-478  GATES, P. 2005. High performance liquid chromatography-mass spectrometry (HPLC/MS). Organic Chemistry Unit-Bristol Research Centre  LAST, R.L., JONES, A.D. & SHACHAR-HILL, Y. 2007

Lab Report On Gas Chromatograph And The Optical Activity Of Carvones

680 words - 3 pages activity of 0.516 and that spearment oil is 59% carvone and caraway oil is 100% carvone.Backround:Gas Chromatography separates organic samples much in the same way as column chromatography. The only differences are that it uses a moving gas phase and a stationary liquid phase, and that the temperature of the gas system can be controlled. In a gas chromatograph the sample is shot in with a syringe and is immediately vaporized in a heated injection