Acids and alkalis can be found in many different products and places, including the acid in our stomach and some of the products your parents use to clean the house are alkaline solutions. Using a scale called pH, scientists can see how acidic or alkaline a solution is, acidic solutions have a low pH, while alkaline solutions have a high pH. Very strong acids and alkalis are very harmful to both humans and our environment, so it is important that scientists can measure pH. Being able to measure pH allows us to ensure the water we are drinking is a good quality as well as allowing us to safely store foods for longer periods.
In chromatography being able to measure and control the pH of our mobile phase allows scientists to retain and separate a mixture of different compounds.