HPLC A Practical User’s Guide P2

I recommend a dynamically stirred, two-pump, high-pressure mixing system. If, on the other hand, you’ll mainly be doing scouting gradients, dial-a-mix isocratics, and the occasional uncomplicated gradient, the low-pressure mixing system would be excellent and save you about $4,000. This system has the advantage of giving you three- or four-solvent capability, which would be of advantage in scouting and automated wash-out, but it requires continuous, inert gas solvent degassing. I generally find low-pressure mixing gradient reproducibility performance to be about 95% that of the high-pressure mixing system. Gradients from 0 to 5% and 95 to 100% B may be worse...