The brine salts reduce the hydration of extracted molecules. Therefore, the substance is transferred to the extractant additionally .
It is not brine specifically but the presence of Sodium Chloride or common table salt that is used to 'salt' out organic species.
The process of synthesizing and isolating an organic compound often results in an organic compound or solution contaminated with traces of water. For instance, in aqueous extractions some water will be transferred into the organic phase because of the partial miscibility of the organic phase and water. Also, many reactions themselves are performed in an aqueous solution. This water must be removed before the required compound can be properly characterized.
Saturated Aqueous Sodium Chloride
The bulk of the water can often be removed by shaking or "washing" the organic layer with saturated aqueous sodium chloride (otherwise known as brine). The salt water works to pull the water from the organic layer to the water layer. This is because the concentrated salt solution wants to become more dilute and because salts have a stronger attraction to water than to organic solvents.
To dry your organic product by this method, place the organic solution in a separatory funnel. The organic solvent can be any solvent that is immiscible with water. Add an amount of saturated aqueous sodium chloride, less than or equal to the amount of organic solution you have.
Stopper the funnel and shake as in an extraction. Allow the layers to separate. The rules as to which layer is on top are the same as for extraction. Since there is a lot of salt dissolved in the water, the density of the saturated aqueous sodium chloride solution is 1.2 g/mL. Drain off the lower layer. In this case, this is the organic layer and the layer you want to save. Dispose of the aqueous layer in the aqueous waste carboy. (In some cases, for instance if you are using diethyl ether, the upper layer will be the desired organic layer.
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- Analytical Chemistry
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