Singapore Lipidomics Incubator (SLING), Life Sciences Institute, National University of Singapore, Singapore, Singapore.
Singapore Lipidomics Incubator (SLING), Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
Metabolomics. 2020 Apr 17;16(5):53. doi: 10.1007/s11306-020-01677-z.
High quality data, based on reliable quantification and clear identification of the reported lipid species, are required for the clinical translation of human plasma lipidomic studies.
Lipid quantification can be efficiently performed on triple quadrupole (QqQ) mass spectrometers in targeted multiple reaction monitoring (MRM) mode. However, a series of issues can be encountered when aiming at unambiguous identification and accurate quantification, including (i) resolving peaks of polyunsaturated species, (ii) discriminating between plasmanyl-, plasmenyl- and odd chain species and (iii) resolving the isotopic overlap between co-eluting lipid species.
As a practical tool to improve the quality of targeted lipidomics studies, we applied a Dual MS platform by simultaneously coupling a reversed-phase liquid chromatography separation to a QqQ and a quadrupole-time of flight (Q-ToF) mass spectrometers. In one single experiment, this platform allows to correctly identify, by high-resolution MS and MS/MS, the peaks that are quantified by MRM.
As proof of concept, we applied the platform on glycerophosphocholines (GPCs) and sphingomyelins (SMs), which are highly abundant in human plasma and play crucial roles in various physiological functions. Our results demonstrated that Dual MS could provide a higher level of confidence in the identification and quantification of GPCs and SMs in human plasma. The same approach can also be applied to improve the study of other lipid classes and expanded for the identification of novel lipid molecular species.
This methodology might have a great potential to achieve a better specificity in the quantification of lipids by targeted lipidomics in high-throughput studies.
为了将人类血浆脂质组学研究转化为临床应用，需要基于可靠的定量和明确的报告脂质物种鉴定来提供高质量的数据。
三重四极杆（QqQ）质谱仪可以在靶向多重反应监测（MRM）模式下高效地进行脂质定量。然而，在明确鉴定和准确定量方面，会遇到一系列问题，包括（i）解析多不饱和物种的峰，（ii）区分酰基-、烷酰基-和奇数链物种，以及（iii）解析共洗脱脂质物种之间的同位素重叠。
作为提高靶向脂质组学研究质量的实用工具，我们应用了双 MS 平台，通过同时将反相液相色谱分离与 QqQ 和四极杆飞行时间（Q-ToF）质谱仪耦合。在单次实验中，该平台允许通过高分辨率 MS 和 MS/MS 正确鉴定由 MRM 定量的峰。
作为概念验证，我们将该平台应用于甘油磷酰胆碱（GPCs）和神经鞘磷脂（SMs），它们在人血浆中含量丰富，在各种生理功能中发挥着关键作用。我们的结果表明，双 MS 可以为鉴定和定量人血浆中的 GPCs 和 SMs 提供更高的可信度。同样的方法也可以应用于提高其他脂质类别的研究，并扩展到鉴定新的脂质分子物种。
该方法在高通量研究中通过靶向脂质组学实现更好的脂质定量特异性具有很大的潜力。
