Question

MCH always comes as a liquid, so I tried first making a stock 10 mM solution by mixing 1 mg of MCH liquid with 745 µL of water. The MCH appeared to be immiscible in water, however, forming distinct droplets in the water that rise to the top without mixing. How do I make a working or stock dilution of MCH in water that isn't biphasic?

Answer 1

To create a dilution of MCH that isn't biphasic, first dissolve it in a polar organic solvent like methanol which is miscible with both MCH and water; then add water and stir to ensure a homogeneous mixture.

Step-by-step explanation:

MCH or methenylcyclohexane is an organic compound and like many organic liquids, it may not be miscible with water. Creating a stock solution or working dilution of a compound that is immiscible in water requires using a solvent in which the compound is soluble. One approach is to first dissolve the MCH in an organic solvent (like methanol or another polar organic solvent) that is miscible with both MCH and water. Once you have a stock solution in an appropriate solvent, you can then proceed with the dilution, ensuring that the final concentration of the organic solvent in water stays within a range where it will remain miscible.

Steps for Dilution of MCH

1. Dissolve MCH in an appropriate volume of an organic solvent, such as methanol, to create a concentrated stock solution.
2. Gradually add water to the organic solution while stirring to mix thoroughly.
3. Adjust the volume to reach the desired final concentration of MCH, making sure the solvent system remains homogeneous.

Always remember to check for the compatibility of your solvent with subsequent reactions or processes, as the choice of solvent can affect your later results. In cases like this, consulting material safety data sheets (MSDS) and solubility guidelines can provide you with necessary details.