On-chip mass spectrometric analysis in non-polar solvents by liquid beam infrared matrix-assisted laser dispersion/ionization

By the on-chip integration of a droplet generator in front of an emitter tip, droplets of non-polar solvents are generated in a free jet of an aqueous matrix. When an IR laser irradiates this free liquid jet consisting of water as the continuous phase and the non-polar solvent as the dispersed droplet phase, the solutes in the droplets are ionized. This ionization at atmospheric pressure enables the mass spectrometric analysis of non-polar compounds with the aid of a surrounding aqueous matrix that absorbs IR light. This works both for non-polar solvents such as n-heptane and for water non-miscible solvents like chloroform. In a proof of concept study, this approach is applied to monitor a photooxidation of N-phenyl-1,2,3,4-tetrahydroisoquinoline.

Automated summary

This approach involves generating droplets of non-polar solvents in an aqueous matrix and ionizing the solutes with an IR laser for mass spectrometric analysis at atmospheric pressure. It works for both non-polar solvents such as n-heptane and water non-miscible solvents like chloroform. It has been successfully applied to monitor the photooxidation of N-phenyl-1,2,3,4-tetrahydroisoquinoline in a proof of concept study.