Normal Phase Applications - Agilent Technologies InfinityLab LC Series User Manual

3 Using the Pump

Normal Phase Applications

Normal Phase Applications

Current passive inlet valves and outlet ball valves used with 1260 and 1290
Infinity pumps do not work well with applications using non-polar solvents as for
normal phase applications (e.g. hexane, heptane and CO
applications, pressure drops could be observed. They are a result of particles
electrostatically charging up in insulating solvents and sticking to the balls inside
the valves, such that the valves do not close properly any more after some time
of use (can be hours).
For normal phase applications, a second type of valves is available, which has a
design based on the existing one for 1260 and 1290 Infinity valves. These valves
use a new material for valve balls, which is a conductive ceramic and replaces
non-conductive ruby balls. The balls do not charge up electrostatically and show
good performance in normal phase.
The valves are marked with N for non-polar or normal phase.
Agilent recommends using these valves for (and only for) normal phase
applications.
Corrosion of valves
C AU T I O N
Normal phase balls/valves corrode quickly in aqueous solutions and acids (at
or below pH 7).
Do not use normal phase valves in applications running with aqueous

solutions.
The N-Valves have been tested successfully in using hexane at pressures below
100 bar; heptane can be used as a substitute for neurotoxic hexane.
Agilent InfinityLab LC Series 1260 Infinity II Isocratic and Quaternary Pumps User Manual
). With such
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