Quantitative magnetic resonance imaging of urea and lysozyme in protein chromatography

Magnetic resonance imaging (MRI) techniques have been implemented to enable quantitative imaging of protein and urea within a 5 ml HiTrap size-exclusion chromatography desalting column, without introduction of contrast agents. One-, two- and three-dimensional images of urea injected at concentrations of 2, 4, 6 and 8 M were acquired. One-dimensional profiles of lysozyme at concentrations between 5 and 25 mg ml−1 were also obtained. All data were accurate to within ±15% when compared to the known amount injected. Quantitative MRI elution profiles of both urea and lysozyme were then obtained in real-time during a desalting separation.