Direct coupling of capillary electrophoresis and nuclear magnetic resonance spectroscopy for the identification of a dinucleotide

Coupling of capillary electrophoresis (CE) with nuclear magnetic resonance (NMR) spectroscopy has been achieved by use of a recently developed capillary NMR interface. The technique has been used for the analysis of synthetic nucleic acids. A crude adenosine dinucleotide synthesized by solid-phase chemistry has been investigated by continuous-flow CE-NMR. The combination of the separation technique and NMR spectroscopy proved well suited to identification of the main components, and to detection of by-products of the synthesis of the nucleotide. Two-dimensional CE-NMR spectra were also acquired in the stopped-flow mode and the TOCSY NMR spectrum thus acquired afforded confirmatory evidence for the structure of the adenosine dinucleotide. All experiments were performed in fully deuterated solvents and using nanoliter amounts of the dinucleotide sample.