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
建立了纺织品中7种苯氧羧酸类除草剂的高效液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)快速检测方法。样品经甲酸酸化的丙酮溶液超声提取两次,无需其它净化过程。液相色谱使用C18反相色谱柱,流动相为醋酸铵水溶液和甲醇,在梯度条件下分析。...建立了纺织品中7种苯氧羧酸类除草剂的高效液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)快速检测方法。样品经甲酸酸化的丙酮溶液超声提取两次,无需其它净化过程。液相色谱使用C18反相色谱柱,流动相为醋酸铵水溶液和甲醇,在梯度条件下分析。在选择反应检测(SRM)负离子模式下进行质谱信号采集,采用两对同位素离子对进行定性和定量分析。选取3种有代表性的纺织品进行方法检出限(LOD)、定量限(LOQ)、线性、回收率和精密度的验证。方法的LOQ为0.9～2.4μg/kg;回收率为85%～106%;相对标准偏差为2%～11%。本方法简便、有效、可靠、灵敏,能够满足国际生态纺织品标准(Oeko-Tex Standard 100)的限量要求,适用于纺织品中苯氧羧酸类除草剂的日常检测及确证。展开更多
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.
文摘建立了纺织品中7种苯氧羧酸类除草剂的高效液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)快速检测方法。样品经甲酸酸化的丙酮溶液超声提取两次,无需其它净化过程。液相色谱使用C18反相色谱柱,流动相为醋酸铵水溶液和甲醇,在梯度条件下分析。在选择反应检测(SRM)负离子模式下进行质谱信号采集,采用两对同位素离子对进行定性和定量分析。选取3种有代表性的纺织品进行方法检出限(LOD)、定量限(LOQ)、线性、回收率和精密度的验证。方法的LOQ为0.9～2.4μg/kg;回收率为85%～106%;相对标准偏差为2%～11%。本方法简便、有效、可靠、灵敏,能够满足国际生态纺织品标准(Oeko-Tex Standard 100)的限量要求,适用于纺织品中苯氧羧酸类除草剂的日常检测及确证。
