Shim-free homebuilt 2 T magnet for NMR spectroscopy with sub-ppm resolution and sub-nanomole sensitivity

Abstract

Nuclear Magnetic Resonance (NMR) spectroscopy is quintessential for molecular characterization and quantification in many research areas. However, a major drawback is the complex and expensive instrumentation, which inhibits a greater use and impact. The required magnet is typically several Tesla strong to allow good sensitivity and adapted with complex shimming systems for sufficient field homogeneity in the standard 0.5 mL sample tubes. Here we show that a home-constructed 2.1 T permanent magnet suffices for NMR spectroscopy with chemical shift resolution and sensitivity that can be tailored to the requirements using home-built microcoils. 1D and 2D, 1H and 19F-NMR spectra are obtained without any shimming of the magnet, with resolution down to 0.3 ppm exploiting a 40 nL microcoil and sub-nanomole detection sensitivity is achieved by light-induced hyperpolarization. The presented paradigm of matching transceiver microcoils to the sweet-spot of home-built magnets allows for a more wide-spread use and democratization of NMR spectroscopy.