一项在实验室内部利用地磁场核磁共振进行J耦合光谱学的研究。

A study of J-coupling spectroscopy using the Earth's field nuclear magnetic resonance inside a laboratory.

作者信息

Liao Shu-Hsien, Chen Ming-Jye, Yang Hong-Chang, Lee Shin-Yi, Chen Hsin-Hsien, Horng Herng-Er, Yang Shieh-Yueh

机构信息

Department of Physics/Graduate Institute of Applied Physics, National Taiwan University, Taipei 106, Taiwan.

出版信息

Rev Sci Instrum. 2010 Oct;81(10):104104. doi: 10.1063/1.3498895.

DOI:10.1063/1.3498895

PMID:21034103

Abstract

In this paper, an instrumentation of the Earth's field nuclear magnetic resonance (EFNMR) inside a laboratory is presented. A lock-in analysis (LIA) technique was proposed to enhance the signal-to-noise ratio (SNR). A SNR of 137.8 was achieved in a single measurement for 9 ml tap water, and the LIA technique significantly enhanced the SNR to 188 after a 10-average in a noisy laboratory environment. The proton-phosphorus coupling in trimethyl phosphate ((CH(3)O)(3)PO) with J-coupling J[H,F]=(10.99±0.013) Hz has been demonstrated. The LIA technique improves the SNR, and a 2.6-fold improvement in SNR over that of the frequency-adjusted averaging is achieved. To reduce the noise in EFNMR, it was suggested that the LIA technique and the first order gradient shim be used to achieve a subhertz linewidth.

摘要

本文介绍了一种在实验室内部进行地磁场核磁共振（EFNMR）的仪器装置。提出了一种锁相分析（LIA）技术来提高信噪比（SNR）。对于9毫升自来水，单次测量的信噪比为137.8，在嘈杂的实验室环境中经过10次平均后，LIA技术将信噪比显著提高到188。已证明在磷酸三甲酯（(CH(3)O)(3)PO）中质子 - 磷耦合的J耦合J[H,F] = (10.99 ± 0.013) Hz。LIA技术提高了信噪比，与频率调整平均相比，信噪比提高了2.6倍。为了降低EFNMR中的噪声，建议使用LIA技术和一阶梯度匀场来实现亚赫兹线宽。