Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), INRA UMR 1329, LUNAM Université, Oniris, Nantes F-44307 , France.
Department of Analytical Chemistry, Faculty of Sciences , University of Granada , Av. Fuentenueva s/n , Granada E-18071 , Spain.
Anal Chem. 2018 Apr 3;90(7):4616-4625. doi: 10.1021/acs.analchem.7b05117. Epub 2018 Mar 20.
Ion mobility spectrometry enhances the performance characteristics of liquid chromatography-mass spectrometry workflows intended to steroid profiling by providing a new separation dimension and a novel characterization parameter, the so-called collision cross section (CCS). This work proposes the first CCS database for 300 steroids (i.e., endogenous, including phase I and phase II metabolites, and exogenous synthetic compounds), which involves 1080 ions and covers the CCS of 127 androgens, 84 estrogens, 50 corticosteroids, and 39 progestagens. This large database provides information related to all the ionized species identified for each steroid in positive electrospray ionization mode as well as for estrogens in negative ionization mode. CCS values have been measured using nitrogen as drift gas in the ion mobility cell. Generally, direct correlation exists between mass-to-charge ratio ( m/ z) and CCS because both are related parameters. However, several steroids mainly steroid glucuronides and steroid esters have been characterized as more compact or elongated molecules than expected. In such cases, CCS results in additional relevant information to retention time and mass spectral data for the identification of steroids. Moreover, several isomeric steroid pairs (e.g., 5β-androstane-3,17-dione and 5α-androstane-3,17-dione) have been separated based on their CCS differences. These results indicate that adding the CCS to databases in analytical workflows increases selectivity, thus improving the confidence in steroids analysis. Consequences in terms of identification and quantification are discussed. Quality criteria and a construction of an interlaboratory reproducibility approach are also reported for the obtained CCS values. The CCS database described here is made publicly available.
离子淌度谱增强了旨在对类固醇进行分析的液相色谱-质谱工作流程的性能特点，为其提供了一个新的分离维度和一个新的特征化参数，即所谓的碰撞截面（CCS）。本工作提出了第一个包含 300 种类固醇（即内源性类固醇，包括 I 相和 II 相代谢物以及外源性合成化合物）的 CCS 数据库，其中涉及 1080 个离子，涵盖了 127 种雄激素、84 种雌激素、50 种皮质类固醇和 39 种孕激素的 CCS。该大型数据库提供了与每种类固醇在正电喷雾电离模式下以及负电喷雾电离模式下的雌激素所鉴定的所有离子化物质相关的信息。CCS 值是使用氮气作为漂移气体在离子淌度池中测量的。通常，质荷比（m/z）与 CCS 之间存在直接相关性，因为两者都是相关参数。然而，一些类固醇，主要是类固醇葡萄糖醛酸苷和类固醇酯，其特征是比预期更紧凑或更长的分子。在这种情况下，CCS 为类固醇的鉴定提供了与保留时间和质谱数据相关的额外相关信息。此外，还根据 CCS 差异对几个异构类固醇对（例如 5β-雄烷-3,17-二酮和 5α-雄烷-3,17-二酮）进行了分离。这些结果表明，在分析工作流程中将 CCS 添加到数据库中可提高选择性，从而提高对类固醇分析的可信度。讨论了在鉴定和定量方面的影响。还报告了获得的 CCS 值的质量标准和构建实验室间重现性方法。此处描述的 CCS 数据库是公开提供的。
