Gas Chromatography

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Neha Bhattacharjee 5/23/11
Upamanyu Basu Gas Chromatography

Part 1: General Questions

1. Gas chromatography is a type of chromatography that allows for separation and analysis of a compound. It does this by vaporizing the sample then using a carrier gas to push it through a column which then separates it based on an equilibrium formed between solution and dissolution. 2. As a gaseous mixture travels down the column parts of the sample dissolve into the liquid. There is equilibrium between the gas phase (solution) and the stationary phase (liquid phase). This is what the partition coefficient is based on; it is the concentration of the sample in the stationary phase over the concentration of the sample in the mobile phase. Based on the properties of the components like vapor pressure they will react differently with the column contents. The higher the vapor pressure the lower the boiling point. If a component has a high vapor pressure then it will move through the column faster. Therefore it will stay in solution longer than other components and reach the detector first. 3. Pentanol elutes last because it has the highest boiling point and based on chain length and it’s the largest molecule. 1-butanol will be next because it has the next highest boiling point based on OH location (Oxygen creates a larger electronegative difference) and is also more polar so it will move slower. T-butanol is the fastest because it has the lowest boiling point and is the least polar. 4. The Kp should be smaller because more of it exists in the gas phase. 5. Diagram

6. It is non-reactive and inert.
7. It should be high enough to instantly vaporize sample or about 10 to 20 degrees higher than the column temperature. 8. A good solid support means that there is a type of dietnous earth packed into the column which when mixed with a liquid allows for good separation through by creating more surface area? A good...
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