But artesunate is a relatively unstable molecule that fragments easily and causes DESI to lose its sensitivity. So Fernandez and his students have now added an alkylamine compound to the alcohol-water mixture to form a stable molecular species, preventing artesunate fragmentation and thereby increasing sensitivity. They call this process "reactive DESI."
DART, on the other hand, involves an ionizing beam of marginally stable helium atoms generated by an electric discharge. The DART ionization mechanism is still not completely understood. In ongoing research, Fernandez and his students are working to interface DART with other instruments to help understand the chemistry behind the methodology.
To date, they have interfaced DART with a mass spectrometer, but the latter is typically too bulky and expensive to use in a field setting. So researchers plan to interface DART with a similar instrument called an ion mobility spectrometer (IMS), which is used in airports to detect explosives. They hope the pair of techniques could be used in the field to screen solid samples of anti-malarial drugs.
"Our findings not only demonstrate the usefulness of DART for rapid screening of counterfeit drugs, but also have unprecedented implications for malaria control," Fernandez and his co-authors report in ChemMedChem. "We foresee that both DART and DESI will have a tremendous impact in a variety of scientific fields, ranging from drug quality control, screening and discovery to biological applications, such as metabonomics and/or proteomics."