Automated capillary liquid chromatography small volume analysis system

A system for automatically analyzing a plurality of liquid chemical samples comprising, in combination,

• a first capillary having an inside diameter of between 50 and 150 microns packed with a porous bed of particles to form an analysis column having an upstream inlet, a downstream outlet, and a branch outlet positioned between said inlet and said outlet at a distance between 10 and 16 centimeters from said outlet, said analysis column forming a pre-concentration trap between said upstream inlet and said branch outlet and forming a chromatography separation column between said branch outlet and said downstream outlet,
• a mass spectrometer positioned to receive chromatography eluent from said downstream outlet,
• an autosampler for delivering said plurality of liquid samples,
• a two-position valve having an open position and a closed position, and
• feed connections coupling said autosampler to said upstream inlet via said two-position valve for injecting one of said liquid samples into said pre-concentration trap via said upstream inlet at a maximum loading flow rate in the range from 0.5 to 50 microliters/minute when said two-position valve is in said open position, for thereafter terminating the further injection of said one of said liquid samples via said upstream inlet when said two-position valve moves to said closed position, and for permitting the passage of a concentrated portion of said one of said liquid samples though said chromatography separation column at a lower flow rate between 10 and 1,000 nanoliters per minute to thereby deliver chromatography eluent through said downstream outlet to said mass spectrometer when said two position valve is in said closed position.

A system for automatically analyzing a plurality of liquid chemical samples comprising, in combination,

• first and second analysis columns each of which comprises a capillary having an inside diameter of between 50 and 150 microns packed with a porous bed of particles to form an analysis column having an upstream inlet, a downstream outlet, and a branch outlet positioned between said inlet and said outlet at a distance between 10 and 16 centimeters from said outlet, said analysis column forming a pre-concentration trap between said upstream inlet and said branch outlet and forming a chromatography separation column between said branch outlet and said downstream outlet, and a mass spectrometer positioned to receive chromatography eluent from said downstream outlet of each of said analysis columns
• an autosampler for delivering said plurality of liquid samples,
• a valve having first and second positions,
• a first set of feed connections coupling said autosampler to said upstream inlet of first analysis column via said two-position valve for injecting a second one of said liquid samples into the pre-concentration trap of said first analysis column via said upstream inlet of said first analysis column at a maximum loading flow rate in the range from 0.5 to 50 microliters/minute when said two-position valve is in said first position, for thereafter terminating the further injection of said first one of said liquid samples via said upstream inlet of said first analysis column when said two-position valve moves from said first to said second position, and for permitting the passage of a concentrated portion of said first one of said liquid samples though said chromatography separation column of said first analysis column at a lower flow rate between 10 and 1,000 nanoliters per minute to thereby deliver chromatography eluent derived from said first one of said liquid samples to said mass spectrometer positioned to receive chromatography eluent from said downstream outlet of said first analysis column when said two position valve is in said second position.