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How to switch HPLC columns using valves. Different analyses sometimes use different columns. But even when the same column can handle more than one kind of sample, many chemists dedicate a column to each analysis. This prolongs column life, reduces interferences, and eliminates equilibration delays. Rheodyne's Technical Notes 4 tells how to use switching valves to connect as many as five columns to a chromatograph. Any column can be selected, while the off-line columns remain sealed at each end. The effect on resolution is shown to be negligible in most cases.
Send for Tech Note # 4 For the well-illustrated tech note, contact Rheodyne, Inc., RO. Box 996, Cotati, California 94928, U.S.A. Phone (707) 664-9050.
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