Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, D-66421, Homburg, Saar, Germany.
J Mass Spectrom. 2012 Jan;47(1):66-71. doi: 10.1002/jms.2027.
In contrast to libraries with highly reproducible gas chromatography electron ionization mass spectra, current liquid chromatography (LC-MS) libraries are limited to specific instrument types. Therefore, the aim of the study was to prove whether a recently developed linear ion trap (LIT) LC-MS(n) screening approach and reference library can be transferred to an LC-MS/MS system with a quadrupole-LIT hybrid mass analyzer using SmileMS, a sophisticated search algorithm. The LIT reference library was built with MS² and MS³ wideband spectra recorded on a ThermoFisher LXQ LIT with electrospray ionization in positive mode and full-scan data-dependent acquisition (DDA). Collision parameter optimizations, including different scan types and energies, were performed on an Applied Biosystems QTRAP 4000 system using electrospray ionization in positive mode and full-scan DDA. Modified library sets were generated to improve the detection of a compound by the used search algorithm. Additionally, 100 authentic human urine samples were screened by both systems for proof of applicability. In the applicability study, 533 compounds were detected by the LXQ and 477 by the QTRAP system using enhanced product ion scan and a modified database. The presented data showed that the LIT screening approach and reference library could be used successfully on a QTRAP instrument with some limitations. These should be overcome by further optimizations regarding DDA settings for better sensitivity and further library modifications to reduce spectra mismatches.
与重现性高的气相色谱电子电离质谱的文库相比，目前的液相色谱（LC-MS）文库仅限于特定的仪器类型。因此，本研究的目的是证明最近开发的线性离子阱（LIT）LC-MS(n)筛选方法和参考文库是否可以使用 SmileMS（一种复杂的搜索算法）转移到具有四极杆-LIT 混合质量分析仪的 LC-MS/MS 系统。LIT 参考文库是使用 ThermoFisher LXQ LIT 建立的，在正模式下进行电喷雾电离，并进行 MS² 和 MS³ 宽带谱记录，采用全扫描数据依赖采集（DDA）。碰撞参数优化，包括不同的扫描类型和能量，在 Applied Biosystems QTRAP 4000 系统上进行，采用正模式电喷雾电离和全扫描 DDA。为了提高所使用的搜索算法对化合物的检测能力，生成了修改后的文库集。此外，还使用两种系统对 100 份真实的人尿液样本进行了筛选，以证明适用性。在适用性研究中，LXQ 系统检测到 533 种化合物，QTRAP 系统检测到 477 种化合物，采用增强的产物离子扫描和修改后的数据库。所呈现的数据表明，LIT 筛选方法和参考文库可以成功应用于 QTRAP 仪器，但存在一些限制。通过进一步优化 DDA 设置以提高灵敏度和进一步修改文库以减少谱图不匹配，可以克服这些限制。
