Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, s...Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview of the derivatization methods in the LC/MS analysis of neurosteroids or neuroactive neurosteroids, which are synthesized and accumulated in the nervous system The derivatization of pregnenolone 3 sulfate, one of these steroids, with 4 ( N,N dimethylaminosulfonyl) 7 hydrazino 2,1,3 benzoxadiazole gave a satisfactory sensitivity during the quantitative analysis using LC/ESI MS The obtained results are much lower than those previously obtained using gas chromatography/mass spectrometry or radioimmunoassay On the other hand, the derivatization to acetate was useful for the treatment of labile catechol estrogens in rat brains and gave enough structural information in LC/APCI MS, which confirmed the existence of catechol estrogens in mammalian展开更多
建立以邻苯二甲醛为衍生试剂,柱前衍生-HPLC测定特殊医学用途奶粉中牛磺酸含量的方法。选用C18色谱柱进行产物分离,并对衍生试剂用量、流动相比例、流速、混合次数、衍生后等待时间等因素进行优化。结果表明衍生试剂用量30μL,流动相体...建立以邻苯二甲醛为衍生试剂,柱前衍生-HPLC测定特殊医学用途奶粉中牛磺酸含量的方法。选用C18色谱柱进行产物分离,并对衍生试剂用量、流动相比例、流速、混合次数、衍生后等待时间等因素进行优化。结果表明衍生试剂用量30μL,流动相体积比20∶80,流速0.6 mL/min,混合6次,衍生完成后等待时间0 min时,衍生物的峰面积和峰形最优。在此实验条件下3种不同浓度牛磺酸标准品的精密度测定衍生物峰面积相对标准偏差(relative standard deviation,RSD)为0.08%~0.75%,精密度高。对两种特殊医学用途奶粉中牛磺酸含量进行检测,重复性实验测定RSD分别为0.67%和0.37%,重复性稳定;样品加标平均回收率分别为97.6%~104.5%和106.0%~110.3%,回收率好。该研究方法反应条件温和、操作性强,适用于特殊医学用途奶粉中牛磺酸含量的测定。展开更多
文摘Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview of the derivatization methods in the LC/MS analysis of neurosteroids or neuroactive neurosteroids, which are synthesized and accumulated in the nervous system The derivatization of pregnenolone 3 sulfate, one of these steroids, with 4 ( N,N dimethylaminosulfonyl) 7 hydrazino 2,1,3 benzoxadiazole gave a satisfactory sensitivity during the quantitative analysis using LC/ESI MS The obtained results are much lower than those previously obtained using gas chromatography/mass spectrometry or radioimmunoassay On the other hand, the derivatization to acetate was useful for the treatment of labile catechol estrogens in rat brains and gave enough structural information in LC/APCI MS, which confirmed the existence of catechol estrogens in mammalian
文摘建立以邻苯二甲醛为衍生试剂,柱前衍生-HPLC测定特殊医学用途奶粉中牛磺酸含量的方法。选用C18色谱柱进行产物分离,并对衍生试剂用量、流动相比例、流速、混合次数、衍生后等待时间等因素进行优化。结果表明衍生试剂用量30μL,流动相体积比20∶80,流速0.6 mL/min,混合6次,衍生完成后等待时间0 min时,衍生物的峰面积和峰形最优。在此实验条件下3种不同浓度牛磺酸标准品的精密度测定衍生物峰面积相对标准偏差(relative standard deviation,RSD)为0.08%~0.75%,精密度高。对两种特殊医学用途奶粉中牛磺酸含量进行检测,重复性实验测定RSD分别为0.67%和0.37%,重复性稳定;样品加标平均回收率分别为97.6%~104.5%和106.0%~110.3%,回收率好。该研究方法反应条件温和、操作性强,适用于特殊医学用途奶粉中牛磺酸含量的测定。
