Response normalized liquid chromatography nanospray ionization mass Spectrometry
Response normalized liquid chromatography nanospray ionization mass Spectrometry
复制标题
DOI：
10.1016/j.jasms.2007.07.022
复制
发表时间：
2007-10-01
影响因子：
3.2
通讯作者：
Alton, Kevin B.
中科院分区：
文献类型：
--
作者：
Ramanathan, Ragu;Zhong, Ruyun;Alton, Kevin B.
对于许多结构不同的化合物观察到的截然不同的 LC-MS 响应限制了 LC-MS 在全扫描检测模式下在不使用参考标准的情况下定量测定药物和代谢物的用途。最近推出的纳喷雾电离 (NSI) 技术在非 LC-MS 条件下显示了一些化合物的类似 MS 响应。然而，在存在许多通常与生物样品（例如尿液、血浆和胆汁）相关的内源性化合物的情况下，需要 LC-MS 来分离、检测、识别和测量单个分析物。设计了 LC-NSI-MS 系统，并在该系统中获得了多种药物及其代谢物的 MS 响应。该装置包括两个高性能液相色谱 (HPLC) 系统、一个基于芯片的 NSI 源和一个四极杆飞行时间 (Q-TOF) 质谱仪。在本文中，这被称为响应归一化液相色谱NSI-MS（RNLC-NSI-MS）系统。一个 HPLC 单元执行分析分离，而另一个单元则在柱后添加与流动相组成完全相反的溶剂，以便进入 NSI 源的最终组合物在整个 HPLC 运行中是等度的。从四种不同结构类别的化合物[vicriviroc (VCV)、地氯雷他定 (DL)、甲苯磺丁脲和可卡因]及其代谢物获得的数据表明，通过在整个 HPLC 运行过程中保持溶剂成分不变，可以最大限度地减少溶剂环境对电离效率的影响。与从放射色谱获得的响应相比，传统 LC-ESI-MS 的响应分别高估了 VCV 和 DL 响应 6 倍和 20 倍。尽管使用 LC-NSI-MS 获得的 VCV 和 DL 响应与各自的放射色谱响应相差 2 至 6 倍，但响应归一化修改导致所有评估化合物的 LC-NSI-MS 响应几乎一致。
The widely different LC-MS response observed for many structurally different compounds limits the use of LC-MS in full scan detection mode for quantitative determination of drugs and metabolites without using reference standard. The recently introduced nanospray ionization (NSI) technique shows comparable MS response for some compounds under non-LC-MS conditions. However, in the presence of numerous endogenous compounds commonly associated with biological samples such as urine, plasma, and bile, LC-MS is required to separate, detect, identify, and measure individual analytes. An LC-NSI-MS system was devised and the MS response obtained in this system for a variety of pharmaceutical drugs and their metabolites. The set-up involves two high-performance liquid chromatography (HPLC) systems, a chip-based NSI source and a quadrupole-time-of-flight (Q-TOF) mass spectrometer. Herein this is referred to as the response normalized-liquid chromatography NSI-MS (RNLC-NSI-MS) system. One HPLC unit performs the analytical separation, while the other unit adds solvent post-column with an exact reverse of the mobile phase composition such that the final composition entering the NSI source is isocratic throughout the entire HPLC run. The data obtained from four different structural classes of compounds [vicriviroc (VCV), desloratadine (DL), tolbutamide, and cocaine] and their metabolites indicate that by maintaining the solvent composition unchanged across the HPLC run, the influence of the solvent environment on the ionization efficiency is minimized. In comparison to responses obtained from radiochromatograms, responses from conventional LC-ESI-MS overestimated the VCV and DL responses, respectively, by 6- and 20-fold. Although VCV and DL responses obtained using LC-NSI-MS are within 2- to 6-fold from the respective radiochromatographic responses, the response normalization modification results in nearly uniform LC-NSI-MS response for all compounds evaluated.