title: Portable microcoil NMR detection coupled to capillary electrophoresis.
abstract: 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 (19)F NMR spectra. Separations of fluorinated molecules are demonstrated with stopped- and continuous-flow NMR detection. The results demonstrate that coupling CE to a portable NMR instrument is feasible and can provide a low-cost method to obtain structural information on microliter samples. An LOD of 31.8 nmol for perfluorotributylamine with a resolution of 4 ppm has been achieved with this system.
authors.affiliation: Department of Analytical Chemistry, Faculty of Natural Sciences, Leibniz University Hanover, Hanover, Germany.
authors.forename: Joana
authors.initials: J
authors.lastname: Diekmann
authors.forename: Kristl L
authors.initials: KL
authors.lastname: Adams
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Klunder
authors.forename: Lee
authors.initials: L
authors.lastname: Evans
authors.forename: Paul
authors.initials: P
authors.lastname: Steele
authors.forename: Carla
authors.initials: C
authors.lastname: Vogt
authors.forename: Julie L
authors.initials: JL
authors.lastname: Herberg
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D005466:Fluorocarbons / Q000737:chemistry / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D018511:Systems Integration; D014269:Trifluoroacetic Acid / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D005466:Fluorocarbons; D014269:Trifluoroacetic Acid