Development of a SPE-LC/MS/MS method for simultaneous quantification of baicalein, wogonin, oroxylin A and their glucuronides baicalin, wogonoside and oroxyloside in rats and its application to brain uptake and plasma pharmacokinetic studies - Fong, S Y; Wong, Y C; Zuo, Z (Journal of Pharmaceutical and Biomedical Analysis, 2014)