Liquid Chromatography Lab

Improved Essays
High performance liquid chromatography (HPLC) is a separation technique utilizing differences in distribution of compounds in two phases; called the stationary phase and the mobile phase. The stationary phase designates a thin layer created on the surface of fine particles and the mobile phase designates the liquid flowing over the particles. Under a certain dynamic condition, each component in a sample has a different distribution equilibrium depending upon the solubility in the phases and or molecular size. As a result, the components move at different speeds over the stationary phase and are thereby separated from each other. These components are separated from one another by the column packing that involves various chemical and/or physical interactions between their molecules and the packing particles. These separated components are …show more content…
Mobile phase is constantly fed into the column inlet at a constant rate by a pump. The sample is injected from a sample injector, located near the column inlet. The injected sample enters the column with the mobile phase and the components in the sample migrate through it, passing between the stationary and the mobile phases. Compounds move in the column only when they are in the mobile phase. Compounds that tend to be distributed in the mobile phase therefore migrate faster through the column while compounds that tend to be distributed in the stationary phase migrate slower. In this way, each component is separated on the column and sequentially elutes from the outlet. Each compound eluting from the column is detected by a detector connected to the outlet of the column.
PRINCIPLE OF RP-HPLC
In RP-HPLC compounds are separated based on their hydrophobic character.retension is the result of interaction of then nonpolar components of the solutes and the non-polar stationay phase. Figure 2 High Performance Liquid Chromatography

Related Documents

  • Improved Essays

    In the lipid chromatography experiment, the purpose was to carry out a TLC, thin-layer chromatography, so the substances we wish to separate are absorbed into the thin layer. That being said, the substance that was being tested…

    • 576 Words
    • 3 Pages
    Improved Essays
  • Great Essays

    Rf values were calculated for the spots using Equation 1. (The distance traveled by each spot was measured as the distance between the starting point of the spot and its center of concentration in its final position; the distance traveled by the solvent was measured from the starting line of the spots to the final position of the solvent front.) Separation of compounds by TLC, such as that observed in this experiment, occurs because the compounds are partitioned between the stationary phase (the adsorbent—silica in this case) and the mobile phase (the development solvent). Stronger intermolecular forces between more-polar compounds and the polar adsorbent cause these compounds to move up the plate more slowly than less-polar compounds, whose weaker forces of attraction to the adsorbent are responsible for their tendency to stay in the relatively nonpolar solvent moving up the plate.5 Thus, compounds are separated according to their differing behavior in the adsorbent-solvent system, with their final heights on the plate and Rf values determined, in general, by their relative degrees of polarity. For best results, acetic acid was a necessary component of the development solvent in this experiment because it was a source of protons, which prevented the…

    • 1415 Words
    • 6 Pages
    Great Essays
  • Improved Essays

    The purpose of experiment 1, fractional distillation and gas chromatography, was to separate an unknown organic mixture into two liquids. The primary process of separation was fractional distillation, which utilizes the physical properties of the two unknown volatile liquids. Once the unknown mixture was successfully fractioned, gas chromatography was used to help determine the identity of the two unknown liquids.…

    • 1163 Words
    • 5 Pages
    Improved Essays
  • Superior Essays

    In this experiment, unknown B was a solid mixture containing two compounds of interests, 1,4-dimethoxybenzene and neutral benzoic acid. These compounds were separated by extraction and washing, and liquid-liquid extraction was specifically performed. Extraction is the process by which a compound of interest is selectively removed from impurities, and washing is the process by which unwanted products or impurities are selectively removed from the desired product.…

    • 1338 Words
    • 6 Pages
    Superior Essays
  • Improved Essays

    Cyclohexanol Lab Report

    • 786 Words
    • 4 Pages

    As the retention time of the standard cyclohexanol is 3.959 min, the sixth peak (4.012) of the student mixture, the closest peak, represents cyclohexanol. In the same way, the seventh peak (4.268) represents heptanal whose standard retention time is 4.170. The order of the retention times corresponds to their polarity; polar analyte interacts more strongly with polar columns. Cyclohexanol has one electronegative atom with only 6 carbons, but heptanal has one electronegative atom with 7 carbons. Therefore, cyclohexanol is relatively polar than…

    • 786 Words
    • 4 Pages
    Improved Essays
  • Improved Essays

    A technique that was used in this experiment was a distillation, which is a method for separating mixtures, in this case, based on boiling points. Since the components used (water and pinacol solution) are immiscible, each component acts independently, the boiling point of the mixture should be below the boiling point of the lowest boiling component.2 The boiling point of water is 100C while the boiling point of pinacol is 106C, so the distillation was stopped at 100C. An aqueous layer and a pinacolone layer are formed. The bottom layer is the aqueous layer because the density of pinacolone is 0.801 g/mL while…

    • 454 Words
    • 2 Pages
    Improved Essays
  • Superior Essays

    This experiment uses the concept that by calculating the retention factors of an unknown compound by using thin-layer chromatography, recording the melting points, and determining the solubility of that unknown compound, that it is possible to determine what that compound is by comparing it to known compounds that have similar retention factors, melting points, and solubility.…

    • 2190 Words
    • 9 Pages
    Superior Essays
  • Improved Essays

    By collecting the distillate at each temperature plateau, fractions containing a single component can be obtained. However, this technique does not work for solutions in which the boiling points of the components differ by less than about 40°C. In such cases, a plot of the temperature versus volume for a simple distillation would rise gradually and would not produce any plateaus. Additionally, the distillate would still contain a mixture of the volatile components, rather than one pure component. In order to separate the volatile components with similar boiling points, multiple simple distillations would have to be performed on the first fraction of distillate obtained, each one producing a more pure sample of the more volatile component. Because this method is inefficient and yields a very low volume of the target solvent, fractional distillation is instead used to separate a mixture of volatile solvents with similar boiling points. Fractional distillation is a method of separation similar to simple distillation, in that volatile components of a solution are separated based on boiling point. The addition of an insulated column to the distillation apparatus in fraction…

    • 958 Words
    • 4 Pages
    Improved Essays
  • Improved Essays

    Solubility analysis is a method of identifying compounds based on how their behavior in other compounds. Solubility is the ability of a solvent to dissolve a solute. For a solvent to dissolve a solute, it has to be able to break the intramolecular forces of the solute. The intermolecular forces between the solvent and the solute have to be greater than the intramolecular forces between the solute particles. Polar substances dissolve in other polar substances so if an unknown compound dissolves in a known polar compound, one can come to the conclusion that the unknown substance is a polar compound. If it does not…

    • 762 Words
    • 4 Pages
    Improved Essays
  • Decent Essays

    For the Thin-Layer Chromatography (TLC) we tested the unknown A and the unknown B. Unknown A, has a similar Ratio Factor (RF) of the known sample of Caffeine which have a 0.31 mm and for the unknown B, it has a similar RF of Acetaminophen which have a 0.63- 0.69 mm, so me and lab partner concluded that the unknown samples that have similar RF of the known samples are the same materials. For equation 2, which have a 33% volume. Then for equation 3, which is the Areas of; 1- propanol is equivalent to 14.5 cm, 1- butanol is equivalent to 15 cm, 1- pentanol is equivalent to 17.5 cm. For equation 1, the percent of each samples collected are; 1- propanol is 30.9%, 1- butanol is 32.0%, and for 1- pentanol is 37.2%. Finally, for equation 4 the percent…

    • 213 Words
    • 1 Pages
    Decent Essays
  • Improved Essays

    Paper Chromatography

    • 476 Words
    • 2 Pages

    When carrying out the process, drawing an origin line near the bottom of one of the ends on the chromatography paper will be the starting point of the mixtures that you are trying to separate when they move up the paper. At first hand, the paper will be soaked with a solvent to allow a stationary liquid phase (this phase is when the mixture being tested is being carried through). The components of the mixture may be soluble in different ways so choosing a running solvent that is suitable for this will allow the components to be separated out. The running solvent…

    • 476 Words
    • 2 Pages
    Improved Essays
  • Superior Essays

    Gas Chromatography Lab

    • 1038 Words
    • 5 Pages

    Figure’s 6, 7, 8, 9, and 10 address the optimal elution volume of methanol part of the experiment. Figure’s 6, 7, 8, 9, and 10 had elution volumes of 2 mL, 3 mL, 4 mL, 5 mL, and 6 mL respectively. The best retention time separation of the three was the sample with elution volume of 6 mL. Although it did have the most separation, figure 10 compared to figure 9 shows that an elution volume of 5 mL may have slightly better chromatograms. An elution volume of 5 mL was used for the final part of the experiment due to this…

    • 1038 Words
    • 5 Pages
    Superior Essays
  • Improved Essays

    The purpose of the experiment Thin Layer Chromatography was to analyze compounds, Aspirin, a mixture of Tylenol with ethanol, acetaminophen, a mixture of Excedrin with ethanol, Aspirin, and acetaminophen, Anthracene, Benzyl, and Triphenylmethanol by separating them with the help of silica plates.…

    • 623 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    The Thin layer chromatography plate shown in Figure 3 is used to identify compounds as well as determine their purity [9]. The crude product spot moved the same distance as the 2-NBB spot. The 4-NBB spot did not appear on the plate, indicating a low concentration of the substance. 4-NBB should diffuse farther up the TLC plate than 2-NBB due to the difference in polarity.…

    • 1570 Words
    • 7 Pages
    Improved Essays
  • Decent Essays

    Paper chromatography is a widely used method of separation. The lab will show the basic techniques of paper chromatography. In this lab, the separation of the dyes used in two different kinds of candy is performed. The candy dyes may also be compared to solutions of FD&C food dyes.…

    • 618 Words
    • 3 Pages
    Decent Essays