Effect of the hydrogenation solvent in the PHIP-SAH hyperpolarization of [1- 13 C]pyruvate

Instrumentation for Hydrogenative Parahydrogen-Based Hyperpolarization Techniques

“…As the dispersion should happen as fast as possible, injecting heated and pressurized base solution into the organic phase was suggested (a video showing the procedure can be found in ref 222). Instead of using pure hydrophobic chloroform, 223 mixtures containing some (a few %) hydrophilic solvents (i.e., ethanol, methanol) or toluene have been suggested 82,222 to further improve the LL mixing and hydrolysis as well as bubbling N 2 gas through the solution. 82 Ultimately, thanks to the instability of the LL mixture, the two phases separate within a few seconds.…”

“…221 In order to solve this issue, filtration of the aqueous solution through a lipophilic resin (Tenax TA, Porous Polymer Adsorbent, 60−80 mesh, Supelco) was recently shown to lead to a reduction of the concentration of these solvents well below the concentration recommended by the Environmental Protection Agency (EPA). 69,222 Heterogeneous Catalysts. In contrast to homogeneous catalysis, heterogeneous catalysis affords straightforward separation of the solution-state hyperpolarized hydrogenation products from the solid catalyst due to the insolubility of the latter.…”

“…Its efficiency depends on the level of dispersion of small droplets of the organic solution into the aqueous phase, as hydrolysis likely occurs at the LL interface. As the dispersion should happen as fast as possible, injecting heated and pressurized base solution into the organic phase was suggested (a video showing the procedure can be found in ref ). Instead of using pure hydrophobic chloroform, mixtures containing some (a few %) hydrophilic solvents ( i.e.…”

“…Instead of using pure hydrophobic chloroform, mixtures containing some (a few %) hydrophilic solvents ( i.e. , ethanol, methanol) or toluene have been suggested , to further improve the LL mixing and hydrolysis as well as bubbling N 2 gas through the solution . Ultimately, thanks to the instability of the LL mixture, the two phases separate within a few seconds.…”

“…Nevertheless, it must be mentioned that, even when pure hydrophobic solvents (chloroform and toluene) were used, their dissolution and ultimately the concentration in the aqueous phase is non-negligible and a cytotoxicity effect has been observed . In order to solve this issue, filtration of the aqueous solution through a lipophilic resin (Tenax TA, Porous Polymer Adsorbent, 60–80 mesh, Supelco) was recently shown to lead to a reduction of the concentration of these solvents well below the concentration recommended by the Environmental Protection Agency (EPA). , …”