Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, 1 Xian Nong Tan Street, Beijing 100050, China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2010 Aug 15;878(24):2292-7. doi: 10.1016/j.jchromb.2010.06.040.
A rapid, simple and sensitive HPLC-ESI-MS/MS method was developed for the simultaneous determination of capsaicin and dihydrocapsaicin in rat plasma. Plasma samples containing capsaicin, dihydrocapsaicin and phenacetin (internal standard) were prepared based on a simple protein precipitation by the addition of two volumes of acetonitrile. The analytes and internal standard were separated on a Zorbax SB-C18 column (3.5microm, 2.1mmx100mm) with mobile phase of acetonitrile/water (55:45, v/v) containing 0.1% formic acid (v/v) at a flow rate of 0.2mL/min with an operating temperature of 25 degrees C. Quantification was performed on a triple quadrupole mass spectrometer equipped with electrospray ionization (ESI) source by selected reaction monitoring (SRM) of the transitions at m/z 306-137 for capsaicin, m/z 308-137 for dihydrocapsaicin and m/z 180-110 for the IS. Linear detection responses were obtained for capsaicin and dihydrocapsaicin ranging from 1 to 500ng/mL and the lower limits of quantitation (LLOQs) for the two compounds were 1ng/mL. The intra- and inter-day precisions (R.S.D.%) were within 9.79% for the two analytes, while the deviations of assay accuracies were within +/-10.63%. The average recoveries of the analytes were greater than 89.88%. The analytes were proved to be stable during all sample storage, preparation and analytic procedures. The method was successfully applied to the pharmacokinetic studies of capsaicin and dihydrocapsaicin in rats after subcutaneous administration of capsaicin (natural, containing 65% capsaicin and 35% dihydrocapsaicin).
建立了一种快速、简单、灵敏的 HPLC-ESI-MS/MS 法，用于同时测定大鼠血浆中的辣椒素和二氢辣椒素。采用两倍体积乙腈沉淀蛋白，制备含辣椒素、二氢辣椒素和非那西汀（内标）的血浆样品。采用乙腈/水（55:45，v/v）为流动相，其中含 0.1%甲酸（v/v），流速为 0.2mL/min，柱温为 25°C，在 Zorbax SB-C18 柱（3.5μm，2.1mm×100mm）上分离分析物和内标。采用电喷雾电离（ESI）源，三重四极杆质谱，以 m/z 306-137 对辣椒素、m/z 308-137 对二氢辣椒素、m/z 180-110 对内标进行选择反应监测（SRM）定量。辣椒素和二氢辣椒素的线性检测响应范围为 1~500ng/mL，两种化合物的定量下限（LLOQ）均为 1ng/mL。两种分析物的日内和日间精密度（RSD%）均在 9.79%以内，而测定准确度的偏差均在±10.63%以内。分析物的平均回收率均大于 89.88%。该方法成功应用于辣椒素（天然，含 65%辣椒素和 35%二氢辣椒素）皮下给药后大鼠体内辣椒素和二氢辣椒素的药代动力学研究。
