Buckenmaier Kai, Neumann Richard, Bullinger Friedemann, Kempf Nicolas, Povolni Pavel, Engelmann Jörn, Samlow Judith, Hövener Jan-Bernd, Scheffler Klaus, Ortmeier Adam, Plaumann Markus, Körber Rainer, Theis Thomas, Pravdivtsev Andrey N
High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen 72076, Germany.
Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Hospital Schleswig-Holstein (UKSH), Kiel University, Kiel 24118, Germany.
Anal Chem. 2025 Aug 19;97(32):17336-17344. doi: 10.1021/acs.analchem.5c00874. Epub 2025 Jul 25.
This study develops the two-field correlation spectroscopy (COSY) in zero to ultralow field (ZULF) liquid state nuclear magnetic resonance (NMR). We demonstrated the successful integration of signal amplification by reversible exchange (SABRE) hyperpolarization with two-dimensional (2D) NMR spectroscopy, enabling the detection of ZULF COSY spectra with increased sensitivity. Field cycling allowed the acquisition of two-field COSY spectra at varying magnetic field strengths, including zero-field conditions. This enabled insight into both -coupling and Zeeman-dominated regimes, benefiting from ultralow field observation sensitivity and mitigating the low-frequency noise by conducting readout at higher fields (>5 μT). Our study explores the effects of polarization transfer, apodization techniques, and the potential for further application of ZULF NMR in chemical analysis exemplified for three X-nuclei and three corresponding molecules: [1-C]pyruvate, [N]acetonitrile, and [3-F]pyridine. These findings pave the way for more sensitive and cost-effective NMR spectroscopy in low-field regimes.
本研究开发了零至超低场（ZULF）液态核磁共振（NMR）中的双场相关光谱法（COSY）。我们展示了通过可逆交换进行信号放大（SABRE）超极化与二维（2D）NMR光谱的成功整合，从而能够以更高的灵敏度检测ZULF COSY光谱。场循环允许在包括零场条件在内的不同磁场强度下采集双场COSY光谱。这使得能够深入了解偶合和塞曼主导的区域，受益于超低场观测灵敏度，并通过在较高场强（>5 μT）下进行读出减轻低频噪声。我们的研究探讨了极化转移、变迹技术的影响，以及ZULF NMR在化学分析中的进一步应用潜力，以三种X核和三种相应分子为例：[1-C]丙酮酸、[N]乙腈和[3-F]吡啶。这些发现为低场区域更灵敏且经济高效的NMR光谱学铺平了道路。
