UPLC–MS–MS Analysis of Baicalin in the Cerebrospinal Fluid of Rabbits: Application to a Pharmacokinetic Study

A sensitive and selective ultra-performance liquid chromatographic–tandem mass spectrometric method has been developed for analysis of baicalin in the cerebrospinal fluid of rabbits. Samples were separated on a C18 column with a gradient prepared from acetonitrile and 0.3% aqueous formic acid solution as mobile phase. The target compounds were quantified by multiple reaction monitoring (MRM) using electrospray ionization (ESI). Intra-and inter-day accuracy, precision, and linear range were investigated in detail. The lower limit quantification (LOQ) was 0.108 ng mL−1. The method has been successfully used for evaluation of the pharmacokinetics of baicalin in 12 rabbits.