The Use of Mass Spectrometry for Off-Line Monitoring of Liquid Chromatography

LC/MS coupling

“…The nozzle (3) produces a supersonic molecular beam (4). The skimmer (5) discards solvent molecules which are pumped away (6). Solute molecules are transmitted in the MS side; then they are ionized and mass analyzed 684 A • ANALYTICAL CHEMISTRY.…”

“…A beam of electron (not represented) is focused inside the source block for producing Cl reactions. Primary and secondary ions exit from the plate (6) and are mass analyzed MS source block. The consumption of liquid nitrogen can be as low as a few liters (5-10) per day, and the regeneration of the trap can be carried out in 15 min or less, depending on the particular design of the device.…”

“…Thus, some researchers still consider that an off-line technique (5)(6)(7), with the independent collection of liquid fractions eluted from an LC column, evaporation of the solvent, and transfer of the solute onto the MS solid probe, is the only realistic LC/MS method. Indeed, the different steps of off-line LC/MS methods can be simplified and automated.…”