Patent ID: 6893569
Filing Date: 2005-05-17
Classification: G01N

Abstract:
1. A method of operating a HPLC instrument having a constant flow rate pump, and a flow line from the pump serially through a sampler, column, and detector, the improved steps of discharging a pure liquid solvent from the HPLC pump under high pressures to provide a steady and constant flow rate through the flow line, sampler, column and detector; separately discharging at a tee connection into the flow line between the HPLC pump and the column a concentrated buffer liquid that is at a flow rate that will provide an intended buffer/solvent dilution ratio, compared to the intended constant flow rate from the HPLC pump; detecting any variance of the HPLC pump pressure in the flow line and responsive thereto of adjusting the rate of flow of the buffer into the line, by increasing it responsive to higher detected line pressures and decreasing it responsive to lower detected line pressures, operable toward maintaining the intended buffer/solvent dilution ratio constant.