Potassium hydroxide solution 10% for the fast hydrolysis of esters for analysis

The applicability of a five-minute hydrolysis method with 10% potassium hydroxide in an alcohol-water (80-20) mixture was investigated for the quantitative determination of certain esters (aspirin, benzocaine, benzyl benzoate, methyl paraben, phenyl salicylate, procaine hydrochloride, propyl paraben, salicylanilide and 0-salicylsalicylic acid) and salicylamide. The results indicate that the method is satisfactory for all but methyl paraben and propyl paraben.