Cold‐spray ionization mass spectrometry of the choline chloride‐urea deep eutectic solvent (reline)

Cold-Spray Ionization mass spectrometry (CSI-MS) that can be compared to an electrospray ionization (ESI) source acting with a nebulizing gas cooled by liquid nitrogen is used for analyzing reline as Deep Eutectic Solvent (DES). The association of cholinium chloride salts urea molecules evidenced in negative CSI-MS through the adduct formation. structure supramolecular assemblies forming ions are observed on CSI spectra rationalized chemical quantum calculations. theoretical studies indicate ionic network organization only supported maximization hydrogen bonds chlorides hydroxyl and methyl moieties cations amino groups urea. gas-phase fragmentation supra-molecular detected performed using in-source collision-induced dissociation experiments. experimental measurements CSI-MS, interpreted at light molecular modelization results, suggest insertion adducts does not lead most stable ions.