High-Pressure Gradient System

In a high-pressure gradient system, each partial flow is delivered via a separate pump into the mixing chamber against the pressure of the column. Differences in volume contraction and compressibility, as observed in most solvent mixtures, are not important during delivery but when mixing the solvents on the high-pressure side of the pump.

Unlike Low-Pressure Gradient Systems, the delivered volume of each partial flow can be determined precisely in high-pressure gradient systems. The gradient profile is more precise and can be achieved with relatively simple pumps. However, the costs for the additional pump are disadvantageous.

 Tip:

Due to solvent compressibility and differing dead volumes, the chromatographic conditions of high-pressure and low-pressure gradient systems are not interchangeable.