Interdisciplinary Nanoscience Center and Department of Chemistry , Aarhus University , Gustav Wieds Vej 14 , DK-8000 Aarhus C, Denmark.
Anal Chem. 2019 Feb 19;91(4):3035-3042. doi: 10.1021/acs.analchem.8b05416. Epub 2019 Feb 6.
We investigate the potential of P NMR with simple, maintenance-free benchtop spectrometers to probe phospholipids in complex mixtures. P NMR-based lipidomics has become an important topic in a wide range of applications in food- and health-sciences, and the continuous improvements of compact, maintenance- and cryogen-free instruments opens new opportunities for NMR routine analyses. A prior milestone is the evaluation of the analytical performance provided by P NMR at low magnetic field. To address this, we assess the ability of state-of-the-art benchtop NMR spectrometers to detect, identify, and quantify several types of phospholipids in mixtures. Relying on heteronuclear cross-polarization experiments, phospholipids can be detected in 2 h with a limit of detection of 0.5 mM at 1 T and 0.2 mM at 2 T, while the headgroups of phosphatidylcholine (PC), phosphatidyl-ethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), and phosphatidyl-glycerol (PG) can be unambiguously assigned based on 2D H-P total correlated spectroscopy (TOCSY) spectra. Furthermore, two quantitative methods to obtain absolute concentrations are proposed and discussed, and the performance is evaluated regarding precision and accuracy.
我们研究了使用简单、无需维护的台式光谱仪进行 P NMR 探测复杂混合物中磷脂的潜力。基于 P NMR 的脂质组学已成为食品和健康科学中广泛应用的重要课题，而紧凑、无需维护和无需制冷剂的仪器的不断改进为 NMR 常规分析开辟了新的机会。一个先前的里程碑是评估低磁场下 P NMR 提供的分析性能。为了解决这个问题，我们评估了最先进的台式 NMR 光谱仪在混合物中检测、识别和定量几种类型磷脂的能力。依靠异核交叉极化实验，在 1 T 时可以在 2 小时内检测到磷脂，检测限为 0.5 mM，在 2 T 时为 0.2 mM，而基于 2D H-P 全相关光谱（TOCSY）谱，可以明确分配磷脂酰胆碱（PC）、磷脂酰乙醇胺（PE）、磷脂酰肌醇（PI）、磷脂酰丝氨酸（PS）和磷脂酰甘油（PG）的头基。此外，还提出并讨论了两种获得绝对浓度的定量方法，并评估了其在精密度和准确性方面的性能。
