“Prep up” in NP with a Step Gradient and “Check Purity” in RP on the Same Column

Two compounds with similar Polarity but different Function Groups, that can be typically Resolved in Isocratic Reversed Phase conditions, are more Separated using this Method with Normal Phase Conditions (non Polar Solvents); without the characteristic hassles associated with Silica or other “Normal Phase” Columns. Chromatograms A and B can be used to test for purity of either sample.

The Step Gradient shown in Chromatogram C below, offers the Chromatographer extra Capacity to Load much more onto the Column and therefore may be able to use a 250mm x 4.6mm ID Column to “Prep Up” these compounds. The ability to “Prep Up” and check purity on the same Column offers time savings and ease of use and improved efficiency of your SOP.

Method Conditions
Column: Cogent Bidentate C18™, 4μm, 100Å
Catalog No.: 40018-75P
Dimensions: 4.6 x 75mm
Mobile Phase Solvents:
A: Hexane
B: Tetrahydrofuran (THF)
Flow rate: 1mL / minute
Detection: UV @ 255nm


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