The chemical formula of brine solution is Na+ (aq) Cl (aq). This aqueous solution of common salt is mainly used as a preservative. It is called sodium chloride solution in the chemistry laboratory.
A brine solution of differing concentrations can be prepared by dissolving different amounts of salt in a given quantity of water. A 10 percent brine solution would have more salt in it than a 5 percent brine solution. Sea water is similar to a 3.5 percent brine solution. Fresh water also contains some amount of salt dissolved in it.
Meat, fish, fruits and vegetables can be preserved by immersing them in brine solution. It is the cheapest way to preserve food.