Advantages And Disadvantages Of Gas Chromatography

Lycopene and β-carotene are separated using thin layer chromatography (TLC). A mixture of tomato paste containing dissolved lycopene and β-carotene is first spotted on a TLC plate. The technique uses a stationary phase layer, on which the substances stick, and a mobile phase, which migrates upwards the plate and carries the components of the mixture with itself (Chemguide). Depending on their respective polarity, lycopene and β-carotene stick more or less to the stationary phase and so they migrate up the TLC plate at different rates (Chemguide). Thus, as the chromatography is completed, the two components will appear as distinct dots at different heights on the plate. Lycopene has a bright orange color, whereas β-carotene is light yellow.

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

Triglyceride concentrations in the liver are much higher than the heart and kidney. The differences between triglyceride and glycerol concentrations were triglyceride includes the free glycerol plus the glycerol. Pure glycerol concentrations were not determined because of reagent availability. The triglyceride concentrations were assumed to be proportional to glycerol concentrations. (Figure 2)

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

Glycerol standard sample was given to the class. One sample of 3 ml Triglyceride reagent was heated at 37°C for 5 minutes, then mixed with 30 µl of Bos taurus homogenate and incubated for 10 more minutes at the same temperature. Absorbance of the glycerol standard and homogenates were measured, and converted to concentration of glycerol (Clendening).

This solution was also the only reagent that turned red and therefore the only reagent that contained the lipid macromolecule. This colour change to red is observed as Sudan III is a lipid soluble solvent dye (lysochrome). In general this dye combines with triglycerols to form these red droplets and emulsion (Pohle, Brändlein, Ruoff, Müller-Hermelink, & Vollmers, 2004). This same colour change occured when Sudan III was added to the lipid solution in this experiment. Therefore it can be concluded that the unknown solution did not contain any lipids as it did not give the expected results for when lipids are

• Due to its high separation efficiency, the quality of substance obtained by preparative mode or technique (prep HPLC) is of high purity.

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.

Groups that contained oxygen were carbonyl (C=O) and alcohol (C-OH) with each bonding present for a different activity based on the location and also with a hybridization of C-O bond. The presence of carbonyl (C=O) did appear in treated glycerol at 1645.6200 cm-1 but not in commercial glycerol. This is caused by some impurities during product oxidation of glycerol for example glyceraldehydes, dihydroxyacetone and also free fatty acids (Yong et al., 2001). The alcohol group (C-OH) also appears in treated and commercial glycerol at a spectra value of 1015.2800 cm-1 and 1038.5400

The Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (EPDETHBCA) (2001), made the low density lipoprotein (LDL) their primary target of therapy, which is the major cholesterol carrying lipoprotein particle in plasma, is primarily derived from lipoprotein particles made by the liver, as the levels of LDL cholesterol increase, the risk of developing CVD increases. An estimated of 13.8% of adults have total serum cholesterol levels ≥240 mg/dL (Go et al., 2014). Saturated fatty acid and trans fatty acid intakes tend to increase LDL, which are the strongest dietary causes of elevated LDL concentrations (Lichtenstein, Ausman, Jalbert & Schaefer, 1999). The increase LDL cholesterol and reduce high density lipoprotein (HDL) cholesterol, cause endothelial damages which is the first stage in the development of atherosclerosis and may cause thrombosis afterwards (Thomas et al., 2007). Inflammation under lies atherosclerosis can be influenced positively by anti-inflammatory diet (Thomas et al., 2007). Independent of

In this experiment, there are one hundred known samples being tested under nine different conditions. Reversed-phase HPLC is being used with water and methanol as the solvents. The columns used are C8, C16, and C18. The number represents the length of carbon chains within the column. Each sample is run on each column under three different solvent ratios: 30%/70% water/methanol, 50%/50% water/methanol, and 70%/30% water/methanol.

In thin-layer chromatography a liquid is pumped across a bed of particles. The liquid that is pumped across is called the mobile phase and the particles are the stationary phase. A mixture of the molecules that will be separated is put into the mobile phase. Thin-layer chromatography tells you/helps you determine the number of compounds in a mixture, the purity of a compound, and the identity of compounds if you have examples to pull information from. Thin-layer chromatography is used to separate nonvolatile mixtures. The dye that was the most polar was the color red and pink which was Rhodamine B and the least polar was the light pink color which was Sudan IV. Our first TLC plate had five

     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.

Once the solvent line has risen, the plate was removed and allowed to dry, and the solvent line marked. Once the TLC plate was dried, it was analyzed under a UV Light and circles placed around visible spots where the solutions had traveled (Figure 3). The Rf values were calculated, Table 3, by using the measured distance the spot

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.