RP-HPLC MICROCHIP SEPARATIONS WITH SUBNANOLITER ON-CHIP PRESSURE INJECTIONS

摘要

On-chip HPLC separations require a fluidic control system that can reliably deliver low-volume, high-pressure fluidic injections. We present a valving scheme that allows for metered, diffusionless, on-chip pressure injections. Microvalves are fabricated using in-situ photopolymerization of a fluorinated acrylate polymer that moves in response to pressure differentials. The valves are inert and can withhold high pressures. In a similar manner, a reversed-phase separation column is fabricated using phase-separation polymerization of a stearyl acyrlate polymer covalently bonded to the microfluidic substrate. The performance of the column is demonstrated by a rapid HPLC separation of a peptide mixture. The on-chip injector is actuated via a pressure differential and can meter sample volumes less than 1nL.