What is the Basic Principle of Solvent Extraction?

What is the Basic Principle of Solvent Extraction?

What is Solvent Extraction?

Solvent extraction is an extraction technique that involves two liquids: an aqueous liquid and an organic liquid. These liquids are mixed with a substance that contains the desired compound and is more soluble in one of them than the other. This is what allows the desired compound to be isolated.

You might be wondering what the basic principle is that causes solvent extraction to work. As it turns out, there is not just one solvent extraction principle; there are a few principles that work together and make this process effective. If you are curious to learn about these principles, read on!

Principles of Solvent Extraction

  • Solvent Extraction Principle #1: Polarity

The first solvent extraction principle has to do with polarity. “Like dissolves like” is a common phrase in chemistry- substances that dissolve in each other have similar polarities. The aqueous solution used in solvent extractions is generally water, which is polar. The organic solution, also called the organic solvent, is nonpolar. Therefore, depending on whether the desired compound is polar or nonpolar, it will be located in one of these liquids after they are mixed in a separatory funnel. This solvent extraction principle is essentially the reason why solvent extraction works!

  • Solvent Extraction Principle #2: Density

The next solvent extraction principle is density. The aqueous and organic solutions used in extraction will form two layers in the separatory funnel, since they cannot mix, and the liquids’ densities must be used to determine which is which. Water has a density of 1 g/mL, so an organic solvent with a higher density will generally be the bottom layer, whereas one with a lower density will be the top layer.

  • Solvent Extraction Principle #3: Temperature

The last solvent extraction principle we will discuss is temperature. Temperature increases solubility- think about dissolving honey in a cup of tea versus a cup of room temperature water. This property can be manipulated by applying heat at some point during the extraction process, which will allow the desired compound to dissolve better in whichever liquid it is soluble in, making the extraction more efficacious overall.

Looking for Extraction Solvents?  

Now you know that there is not just one solvent extraction principle- several principles dictate how and why this extraction technique works. Are you wondering where to purchase solvents to use during extractions? Here at Extraction Grade Solvents, our industrial solutions are perfect for a variety of extraction purposes- plus, we can even create customized products to suit your needs. To learn more, please call us at 800-563-1305, or contact us here!