How the buffer blending valve works – Bio-Rad ChromLab™ Software User Manual
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Valves
Instrument Guide
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How the Buffer Blending Valve Works
The buffer blending valve operates in two modes: buffer blending and gradient.
Buffer Blending Mode
Acid, base, water, and salt are blended together in the required proportions to form
a buffer of specified pH over a linear salt gradient, or a pH gradient at a specified
salt concentration. The suggested buffer solution for each port is
Q4 — high salt buffer solution (green inlet tubing)
Q3 — water (yellow inlet tubing)
Q2 — buffer base (blue inlet tubing)
Q1 — buffer acid (orange inlet tubing)
The Q1 and Q2 acid and base are selected depending on the buffer system being
used.
Gradient Mode
The buffer blending valve enables both pumps simultaneously to run up to their
maximum flow rate, doubling the available flow-rate range for creating gradients.
This is possible because gradients are formed by the proportioning actuation of the
individual Q1 and Q4 valves rather than proportioning the pump speed as in
two-pump gradient mode.
Note:
Only ports Q1 and Q4 are used in gradient mode.