Closed loop flow control of a hplc constant flow pump to enable low-flow operation

摘要

A method and apparatus for monitoring and controlling nano-scale flow rate of fluid in the operating flow path of a HPLC system provide fluid flow without relying on complex calibration routines to compensate for solvent composition gradients typically used in HPLC. The apparatus and method are used to correct the flow output of a typical, analytical-scale (0.1-5 mL/min) HPLC pump to enable accurate anti precise flow delivery at capillary (<0.1 mL/min) and nano-scale (<1 žL/min) HPLC flow rates.