Gradient systems



Abstract Gradient methods, which vary the composition of the mobile phase during a chromatographic run, can improve many aspects of a chromatographic separation, but require special equipment. Low pressure gradient systems use a series of proportioning valves to control the relative composition of the solvent flowing to a single pump. High pressure mixing systems use two pumps whose speeds are adjusted to vary the composition of their combined output to the column. Minimal dwell volume and high mixing efficiency are important to gradient quality.

KeywordsGradient, Valves, Pump, Mobile phase, Low pressure mixing, High pressure mixing, Mixing, Dwell volume

LevelBasic


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