Portable Microcoil NMR Detection Coupled to Capillary Electrophoresis

High-efficiency separation techniques, such as capillary electrophoresis (CE), coupled to a nondestructive nuclear magnetic resonance (NMR) spectrometer offer the ability to separate, chemically identify, and provide structural information on analytes in small sample volumes. Previous CE−NMR coupled systems utilized laboratory-scale NMR magnets and spectrometers, which require very long separation capillaries. New technological developments in electronics have reduced the size of the NMR system, and small 1−2 T permanent magnets provide the possibilities of a truly portable NMR. The microcoils used in portable and laboratory-scale NMR may offer the advantage of improved mass sensitivity because the limit of detection (LOD) is proportional to the coil diameter. In this work, CE is coupled with a portable, briefcase-sized NMR system that incorporates a microcoil probe and a 1.8 T permanent magnet to measure 19F NMR spectra. Separations of fluorinated molecules are demonstrated with stopped- and continuous-f...