In synthetic chemistry, a trituration is a very simple process used to remove soluble impurities from a solid material. It is carried out by vigorously stirring a solid in a large volume of a given solvent in which the main component is insoluble and the impurities are soluble. The vigorous stirring facilitates the grinding of the solid to a fine powder thereby making it easier to extract (wash out) the soluble impurities from the solid. This type of crude purification is typically followed by a more refined purification technique such as a recrystallization.

Things You Will Need

Impure chemical compound
One or more suitable organic solvents
Suitable chemical glassware

Step 1

First you will need to identify a suitable solvent. Your main product should be insoluble or only sparingly soluble in this solvent at room temperature. Your impurities, on the other hand, should be moderately or highly soluble in this solvent at room temperature.

Step 2

Place your impure solid in a round-bottom flask equipped with a magnetic stirrer (or a mechanical overhead stirrer for large quantities) and add the solvent. Aim to use 10-50 ml of solvent per gram of compound for the trituration.

Step 3

Stir your suspension vigorously without spilling. Try to break up any large lumps of solid with a spatula to facilitate the grinding process that is supposed to take place. Continue the stirring for a few hours until a fine powder has formed.

Step 4

Your triturated solid can subsequently be isolated by suction filtration using a Buchner funnel. Wash the solid on the filter with extra solvent and dry it on the filter in air or in a vacuum oven.

In some cases, viscous oils can also be triturated to afford a solid material.

Tips & Warnings

Chemistry experiments should only be done under the supervision of trained chemists in proper chemistry labs using extracted fume hoods.

Always use appropriate personal protective equipment such as safety glasses, lab coats and disposable gloves.