Juan Peris-Vicente et al.
Journal of chromatographic science, 52(9), 1121-1126 (2013-11-14)
A capillary electrophoresis method was developed to quantify caffeine and theophylline, xanthine derivatives with bronchodilator activity. Buffer concentration, pH and applied voltage were optimized using a central composite design-face centred. Separation conditions were: silica capillary tube, 75 μm (i.d.) and