Step 1: Choose the right solvent
The choice of solvent depends on the nature of the sample and the stationary phase. The solvent should be able to dissolve the sample and provide sufficient elution strength to separate the compounds of interest. The solvent should also be compatible with the stationary phase and not cause any degradation or swelling.

Step 2: Prepare the solvent
The solvent should be prepared by using high-quality solvents and deionized water. The solvent should be filtered to remove any particulate matter or impurities that can clog the chromatography column. The solvent should be degassed to remove any trapped air bubbles that can interfere with the separation process.

Step 3: Load the sample
The sample should be loaded onto the chromatography column using a syringe or an automated injector. The sample should be dissolved in a small volume of the solvent to ensure complete dissolution and prevent overloading of the column.

Step 4: Apply the solvent
The solvent should be applied to the column at a constant flow rate using a pump. The flow rate should be adjusted based on the nature of the sample and the stationary phase. The solvent should be allowed to pass through the column until the compounds of interest are eluted.

Step 5: Collect the fractions
As the solvent passes through the column, the compounds of interest will be separated and eluted at different times. The eluted fractions should be collected in individual vials for further analysis. The fractions can be analyzed using various techniques, such as UV-Vis spectroscopy, mass spectrometry, or NMR spectroscopy.

In conclusion, applying a solvent in a chromatography system requires careful consideration of the nature of the sample and the stationary phase. The choice of solvent, preparation of the solvent, loading of the sample, application of the solvent, and collection of the fractions are all important steps in achieving a successful separation and analysis of complex mixtures of compounds.