Lindenburg Petrus W, Ramautar Rawi, Jayo Roxana G, Chen David D Y, Hankemeier Thomas
Division of Analytical Biosciences, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands; Netherlands Metabolomics Centre, Leiden, The Netherlands.
Electrophoresis. 2014 May;35(9):1308-14. doi: 10.1002/elps.201300357. Epub 2013 Dec 20.
The application of CE-MS in the field of metabolomics is underrepresented, even though it is in principle highly suited for the analysis of small charged compounds, as many metabolites are. Moreover, a robust coupling, using the sheath liquid (SL)-assisted interface was already presented more than a decade ago. A lack of concentration sensitivity is often mentioned as a reason for the underrepresentation of CE-MS in metabolomics. This is caused by postcolumn dilution of the sample with SL, which is typically delivered at a flow rate of 1-10 μL/min. In this study, we investigated the performance of the flow-through microvial (MV) assisted CE-MS interface for cationic metabolomics. With this interface, only a little liquid is added postcolumn, that is, typically 100-500 nL/min. For the evaluation, we used a metabolite mix comprising 45 important cationic metabolites and compared the sensitivity and LOD of both devices. The performance of the CE-MS system was significantly improved by using the MV-assisted interface; the sensitivity was increased more than three times and the LOD decreased more than five times. Then, we analyzed single zebrafish embryos to demonstrate the method on a volume-limited biological sample. In comparison with SL-assisted CE-MS, twice as many molecular features were found, of which several could be identified. These results demonstrate the good potential of the MV interface for enhancing the coverage of the metabolome.
尽管从原理上讲，毛细管电泳-质谱联用（CE-MS）非常适合分析许多代谢物这类带电荷的小分子化合物，但它在代谢组学领域的应用却并不多见。此外，早在十多年前就已出现了使用鞘液（SL）辅助接口的强大联用技术。缺乏浓度灵敏度常被认为是CE-MS在代谢组学中应用较少的原因。这是由于样品在柱后被鞘液稀释，鞘液的流速通常为1-10 μL/分钟。在本研究中，我们研究了流通式微量样品瓶（MV）辅助的CE-MS接口用于阳离子代谢组学的性能。通过该接口，柱后仅添加少量液体，即通常为100-500 nL/分钟。为了进行评估，我们使用了一种包含45种重要阳离子代谢物的代谢物混合物，并比较了两种设备的灵敏度和检测限。使用MV辅助接口后，CE-MS系统的性能得到了显著改善；灵敏度提高了三倍多，检测限降低了五倍多。然后，我们分析了单个斑马鱼胚胎，以在体积有限的生物样品上验证该方法。与SL辅助的CE-MS相比，发现的分子特征数量增加了一倍，其中一些可以被鉴定出来。这些结果证明了MV接口在扩大代谢组覆盖范围方面具有良好的潜力。
