Application of a column classification method in a selectivity study involving caffeine and its related impurities

► Comparative study between column selectivity in RP-LC obtained for a real pharmaceutical analysis was presented. ► We performed LC column classification based on the KUL method. ► We evaluated column classification system using system suitability test (SST) and chemometric techniques. ► Factor analysis (FA) was applied. ► The separation of caffeine and its respective impurities was performed.