Ultra-fast determination of caffeine, dipyrone, and acetylsalicylic acid by capillary electrophoresis with capacitively coupled contactless conductivity detection and identification of degradation products - Marra, Mariana Cardoso; Cunha, Rafael Rodrigues; Vidal, Denis Tadeu Rajh; Muñoz, Rodrigo Alejandro Abarza; Lago, Claudimir Lucio do; Richter, Eduardo Mathias (Journal of Chromatography A, 2014)