NMR often does not have sufficient resolution to distinguish between chemicals with related or similar structures in the presence of a large background, which leads to poor chemical specificity. The NMR spectra of complex chemical mixtures may contain unresolved components.

The technology offered here tackles this problem by enhancing the contrast of specific molecules of interest using quantum filtering. The enhanced contrast allows one to distinguish between molecules with very similar structures, such as glutamine and glutamate, which are important metabolites present in the brain. Such molecular distinction could be vital for predicting disease status and progression as well as for assessing the efficacy of drug candidates.

In general, this invention may be useful in all potential uses of NMR spectroscopy—in particular, those that demand a high-resolution chemical analysis. Applications include:

• Spectroscopy of metabolites, small molecules, proteins, and drugs in organs such as the brain, or of bodily fluids
• Spectroscopy of food & beverages, hydrocarbons, and crude oil
• As a diagnostic tool for specific diseases
• Homeland security applications, such as detection of explosives using a chemical signature against confounding background noise
• Spectroscopy of plant tissue to identify metabolites, small molecules, and proteins of plant disease