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

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

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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 ((CH3O)3PO) 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.

Original languageEnglish
Article number104104
JournalReview of Scientific Instruments
Issue number10
Publication statusPublished - 2010 Oct 1


ASJC Scopus subject areas

  • Instrumentation

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