Fast liquid chromatography/time-of-flight mass spectrometry using sol-gel bonded continuous-bed capillary columns

Continuous-bed capillary columns of 50 μm inside diameter, 360 μm outside diameter containing sol-gel bonded large pore octadecylsilica particles (3 μm, 1500 Å) were examined for potential use in fast liquid chromatographic separations. Selected triazine herbicides and benzodiazepines were separated and detected using time-of-flight mass spectrometry. Interfacing and ionization were achieved through a home-built liquid sheath electrospray ionization interface. Demonstration of optimum column performance was achieved through baseline separation of triazine herbicides using a column 25 cm in length. A short column, cut to the minimum physical distance between the column injector and the interface plate of the mass spectrometer (9.3 cm), was used to achieve separation of eight triazine herbicides and seven benzodiazepines in 40 and 35 s, respectively. A maximum syringe pump pressure (43 MPa) was applied to the shortened column, and conditions were optimized to obtain the best separation in the shortest amount of time for both triazine herbicides and benzodiazepines. The advantages of using time-of-flight mass spectrometry as a detector for fast separations are discussed. © 2000 John Wiley & Sons, Inc. J Micro Sep 12: 442–449, 2000