Why is it important to keep the beaker containing the mobile phase covered while preparing your chromatography paper and developing your chromatograms?
It is important to keep the beaker containing the mobile phase covered while preparing your chromatography paper and developing your chromatograms for several reasons:
1. Evaporation prevention: The mobile phase in chromatography typically contains volatile solvents. By keeping the beaker covered, you ensure that the mobile phase doesn't evaporate, which can alter the concentration and composition of the mobile phase over time.
2. Contamination prevention: Keeping the beaker covered protects the mobile phase from airborne impurities or contaminants that may affect the separation process. This helps to maintain the purity and integrity of the mobile phase, leading to accurate and reliable results.
3. Consistent solvent composition: When the beaker is covered, the concentration and composition of the mobile phase remain consistent throughout the chromatography process. This consistency is crucial for reproducible and reliable separation of the analytes on the chromatography paper.
4. Enhancement of separation: Covering the beaker helps maintain a consistent environment around the chromatography paper and promotes a stable condition for optimum separation. This helps to enhance the resolution and efficiency of the chromatographic separation, leading to better identification and quantification of the analytes of interest.
Overall, keeping the beaker containing the mobile phase covered during the preparation and development of chromatograms ensures the stability, accuracy, and reproducibility of the chromatographic analysis.
It is important to keep the beaker containing the mobile phase covered while preparing your chromatography paper and developing your chromatograms because exposure to air can lead to evaporation of the solvent in the mobile phase. This evaporation can change the composition of the mobile phase, leading to inaccurate results in the chromatography process.
To avoid this issue, follow these steps:
1. Prepare your chromatography paper by drawing a baseline near the bottom using a pencil or a marker. Make sure the baseline is straight and free of any smudges.
2. Place your chromatography paper vertically inside a glass or plastic beaker.
3. Pour the mobile phase (solvent) into the beaker, making sure the level of the mobile phase is below the baseline on the chromatography paper. You want the solvent to be in contact with the baseline, but not submerging it.
4. Quickly cover the beaker with a lid, plastic wrap, or a watch glass to prevent evaporation of the solvent.
5. Allow the chromatogram to develop, which involves the solvent moving up the chromatography paper, carrying the components of the sample with it.
Keeping the beaker covered helps maintain the concentration and integrity of the mobile phase, ensuring accurate and reliable separation of the components in your sample during the chromatography process.