在线固相萃取LC-MS/MS法测定比格犬血浆中的知母皂苷B-Ⅱ

目的: 建立简单、快速、自动化的在线固相萃取液质联用法定量测定比格犬血浆中的知母皂苷B-Ⅱ。 方法: 血浆样品直接进样,通过自灌的不锈钢固相萃取柱实现萃取富集过程。采用柱切换技术将被分析物在线洗脱至分析柱上实现色谱分离,最后经过电喷雾电离(ESI)源进入Finnigan线性离子肼质谱仪(LTQ),以选择离子反应 (SRM)模式进行负离子检测。 结果: 知母皂苷B-Ⅱ的线性范围为0.98~1000 ng·mL^-1,最低定量下限为0.98 ng·mL^-1 。日内、日间精密度(RSD)分别小于7.9%和14.2%,准确度(RE)在-1.2%~11.2%范围内。 结论: 该方法成功用于比格犬口服5 mg·kg^-1知母皂苷B-Ⅱ后的药代动力学研究。

Objective: To develop a simple,automatic and rapid quantification method for the determination of timosaponin B-Ⅱ in Beagle plasma. Methods: Raw plasma samples were directly loaded onto a home-packed stainless solid-phase extraction(SPE) column,followed with a timed valve-switching event and elution procedure.The analyte was eluted on-line to a reversed-phase high-performance liquid chromatography(RP-HPLC) column and subsequently introduced into a linear ion trap mass spectrometer,LTQ-MS,via electrospray ionization(ESI) interface.The negative charged compounds were specified and quantitatively analyzed using selective reaction monitoring(SRM) mode.A single analysis run took about 4.7 min. Results: The standard curves for timosaponin B-Ⅱ were linear over the concentration range of 0.98-1000 ng·mL^-1.The lower limit of quantification(LLOQ) was 0.98 ng·mL^-1 .The intra-and inter-batch precisions for timosaponin B-Ⅱ at three quality control levels were less than 7.9% and 14.2%,respectively.The accuracy ranged from -1.2% to 11.2%. Conclusion: The method was successfully applied in the pharmacokinetic(PK) study on Beagles with oral administration of a single dose of 5 mg·kg^-1 timosaponins B-Ⅱ.