Hernández-Mesa Maykel, Monteau Fabrice, Le Bizec Bruno, Dervilly-Pinel Gaud
Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), Oniris, INRA UMR 1329, UBL, Nantes, F-44307, France.
Anal Chim Acta X. 2019 Jan 31;1:100006. doi: 10.1016/j.acax.2019.100006. eCollection 2019 Mar.
In recent years, the commercialization of hybrid ion mobility-mass spectrometers and their integration in traditional LC-MS workflows provide new opportunities to extend the current boundaries of targeted and non-targeted analyses. When coupled to LC-MS, ion mobility spectrometry (IMS) provides a novel characterization parameter, the so-called averaged collision cross section (CCS, Ω), as well as improves method selectivity and sensitivity by the separation of isobaric and isomeric molecules and the isolation of the analytes of interest from background noise. In this work, we have explored the potential and advantages of this technology for carrying out the determination of phase II steroid metabolites (i.e. androgen and estrogen conjugates, including glucuronide and sulfate compounds; n = 25) in urine samples. These molecules have been selected based on their relevance in the fields of chemical food safety and doping control, as well as in metabolomics studies. The influence of urine matrix on the CCS of steroid metabolites was evaluated in order to give more confidence to current CCS databases and support its use as complementary information to retention time (Rt) and mass spectra for compound identification. Samples were only diluted 10-fold with aqueous formic acid (0.1%, v/v) prior analysis. Only an almost insignificant effect of adult bovine urine matrix on the CCS of certain steroid metabolites was observed in comparison with calve urine matrix, which is a less complex sample. In addition, high accuracy was achieved for CCS measurements carried out over four months (ΔCCS < 1.3% for 99.8% of CCS measurements; n = 1806). Interestingly, it has been observed that signal-to-noise (S/N) ratio could be improved at least 2 or 7-fold when IMS is combined with LC-MS. In addition to the separation of isomeric steroid pairs (i.e. etiocholanolone glucuronide and epiandrosterone glucuronide, as well as 19-noretiocholanolone glucuronide and 19-norandrosterone glucuronide), steroid-based ions were also separated in the IMS dimension from co-eluting matrix compounds that presented similar mass-to-charge ratio (). Finally, based on CCS measurements and as a proof of concept, 17α-boldenone glucuronide has been identified as one of the main metabolites resulted from boldione administration to calves.
近年来，混合离子淌度-质谱仪的商业化及其在传统液相色谱-质谱工作流程中的整合，为拓展当前靶向和非靶向分析的边界提供了新机遇。当与液相色谱-质谱联用时，离子淌度谱（IMS）提供了一个新的表征参数，即所谓的平均碰撞截面积（CCS，Ω），同时通过分离等压和同分异构体分子以及从背景噪声中分离出目标分析物，提高了方法的选择性和灵敏度。在本工作中，我们探索了该技术在尿液样本中测定II相类固醇代谢物（即雄激素和雌激素共轭物，包括葡萄糖醛酸苷和硫酸盐化合物；n = 25）的潜力和优势。选择这些分子是基于它们在化学食品安全、兴奋剂检测以及代谢组学研究领域的相关性。评估了尿液基质对类固醇代谢物CCS的影响，以便为当前的CCS数据库提供更多可信度，并支持将其用作保留时间（Rt）和质谱之外用于化合物鉴定的补充信息。分析前样本仅用甲酸水溶液（0.1%，v/v）稀释10倍。与犊牛尿液基质（一种不太复杂的样本）相比，仅观察到成年牛尿液基质对某些类固醇代谢物的CCS有几乎不显著的影响。此外，在四个月内进行的CCS测量实现了高精度（99.8%的CCS测量中ΔCCS < 1.3%；n = 1806）。有趣的是，已观察到当IMS与液相色谱-质谱联用时，信噪比（S/N）可提高至少2倍或7倍。除了分离同分异构类固醇对（即表胆甾醇葡萄糖醛酸苷和表雄酮葡萄糖醛酸苷，以及19-去甲表胆甾醇葡萄糖醛酸苷和19-去甲雄酮葡萄糖醛酸苷）外，基于类固醇的离子在IMS维度上也与共洗脱的具有相似质荷比的基质化合物分离。最后，基于CCS测量并作为概念验证，已鉴定出17α-宝丹酮葡萄糖醛酸苷是给犊牛施用宝丹酮后产生的主要代谢物之一。
