通过固相萃取富集伏马菌素,采用液相色谱-电喷雾串联质谱法测定玉米和芦笋中的伏马菌素B1(FB1)、伏马菌素B2(FB2).在最佳色谱条件下,伏马菌素B1、伏马菌素B2的保留时间分别为5.2 min 和8.8 min,样品空白无干扰.离子化技术采用电喷雾正...通过固相萃取富集伏马菌素,采用液相色谱-电喷雾串联质谱法测定玉米和芦笋中的伏马菌素B1(FB1)、伏马菌素B2(FB2).在最佳色谱条件下,伏马菌素B1、伏马菌素B2的保留时间分别为5.2 min 和8.8 min,样品空白无干扰.离子化技术采用电喷雾正离子方式,以多反应监测(MRM)方式进行检测.该法检出限为80 pg;线性定量范围为0.01～10mg/L;回收率为78.3%～104.9%;相对标准偏差为2.2%～14.2%.利用ESI/MS/MS对伏马菌素B1、伏马菌素B2进行了质谱解析,分别选择特征离子峰m/z 352、528和m/z 336、512作为伏马菌素B1、伏马菌素B2准确定性的依据.方法灵敏度高,选择性好,准确度高,可为食品中伏马菌素的风险评估提供灵敏、准确的分析方法.展开更多
Two kinds of saponins have been investigated by negative electrospray ionization(NESI) mass spectrometry. Under ESI conditions, the - ions of saponins were observed which provide the molecular weights of saponins. The...Two kinds of saponins have been investigated by negative electrospray ionization(NESI) mass spectrometry. Under ESI conditions, the - ions of saponins were observed which provide the molecular weights of saponins. The fragment pathways of - ions of these two saponins depend on their structures. For steroidic saponins, - ion only produces the fragment ions by the losses of sugar units. For oleanolic saponins, - ion yields the cross ring ions as well as the fragment ions by the losses of sugar units. Moreover, the abundance of the former is higher than that of the latter. The characteristic fragments are used to provide the sequence and some linkage information of sugar moieties of saponins. Especially, their fragment difference strongly depends on the linkage between the aglycone and the sugar moieties.展开更多
文摘探针电喷雾电离(probe electrospray ionization,PESI)技术是原位电离技术的典型代表之一,但由于其载样稳定性差,该技术在定量分析中的应用受到很大制约。作者前期对现有PESI技术的定量分析性能进行改进,开发了新型微探针电喷雾串联质谱(micro-pen electrospray ionization tandem mass spectrometry,μPen-ESI-MS/MS)。本研究旨在探索其在药物代谢稳定性及CYP450酶活力评价中的应用。建立检测肝微粒体孵育体系中的CYP3A4底物睾酮与CYP2D6底物右美沙芬的μPen-ESI-MS/MS检测方法,并对分析方法的线性、精密度和准确度进行考察;并应用该分析方法检测睾酮和右美沙芬在肝微粒体孵育体系中的代谢稳定性。结果表明,该μPen-ESI-MS/MS方法分析效率高,一个样品的喷雾时长约为0.3 min。在设定的定量范围内,睾酮和右美沙芬分析方法的标准曲线线性良好(R2>0.99),睾酮的批内和批间准确度为95.9%~109.3%,批内和批间精密度(RSD)为2.4%~13.5%。右美沙芬的批内和批间准确度为90.5%~107.3%,批内和批间精密度(RSD)为3.4%~12.1%。睾酮和右美沙芬在肝微粒体孵育体系中快速代谢(浓度下降一半所需时间分别为12和14 min)。综上,本研究建立了睾酮及右美沙芬的代谢稳定性评价快速灵敏的μPen-ESI-MS/MS分析方法,为药物代谢酶CYP3A4和CYP2D6的活性检测提供了新方法和新策略。
文摘电喷雾电离(electrospray ionization, ESI)易受基质干扰,影响其定量的准确度、精密度和稳定性。探针电喷雾电离(probe electrospray ionization, PESI)是原位电离的代表之一,无色谱分离,无复杂样品前处理,具有简便、快速、高通量等诸多优点。微探针电喷雾串联质谱(micro pen electrospray ionization tandem mass spectrometry,μPen-ESI-MS/MS)是基于现有的PESI开发的新技术。本文旨在评价μPen-ESI-MS/MS方法用于血浆中药物定量分析的基质效应,并与液相色谱-电喷雾串联质谱(liquid chromatography coupled with electrospray ionization tandem mass spectrometry, LC-ESI-MS/MS)方法的基质效应进行比较。分别建立5种药物血浆样品的μPen-ESI-MS/MS和LC-ESI-MS/MS方法,计算两种方法的基质因子及内标归一化的基质因子。结果表明,他克莫司、氟桂利嗪和地氯雷他定的μPen-ESI-MS/MS方法的离子抑制程度等于或小于初步优化后的LC-ESI-MS/MS方法;5种药物内标归一化的基质因子RSD均小于15%,符合中国药典生物样品定量分析方法验证指导原则的相关要求。综上,本研究考察了所建立的μPen-ESI-MS/MS方法用于血浆中药物定量分析的基质效应,为μPen-ESI-MS/MS新方法用于生物样品定量分析提供实验数据和科学依据。
文摘Two kinds of saponins have been investigated by negative electrospray ionization(NESI) mass spectrometry. Under ESI conditions, the - ions of saponins were observed which provide the molecular weights of saponins. The fragment pathways of - ions of these two saponins depend on their structures. For steroidic saponins, - ion only produces the fragment ions by the losses of sugar units. For oleanolic saponins, - ion yields the cross ring ions as well as the fragment ions by the losses of sugar units. Moreover, the abundance of the former is higher than that of the latter. The characteristic fragments are used to provide the sequence and some linkage information of sugar moieties of saponins. Especially, their fragment difference strongly depends on the linkage between the aglycone and the sugar moieties.
