Method Development Users Guide   hQ™ C8

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Use this guide to predict your sample's retention characteristics and elution time on the Cogent hQ™ C8 HPLC Column.

How to Use This Guide
Step 1:	Simply compare the Octanol/Water Partition Coefficient of your acidic, basic or neutral compounds with the appropriate compounds shown.
Step 2:	Read the pH condition at which you will have the best separation with the Generic, LCMS/compatible mobile phase for each compound with this column.     Acids     Bases     Neutrals & DMP*
Step 3:	Predict the optimal pH for your mixture of compounds based on the "retention maps" if you are trying to resolve complex mixtures of acids, bases or neutral compounds.

Included are several examples of different classes of compounds of known Octanol/Water Partition Coefficient (polarity), you can find which pH would be best to use for each of these compound classes with this column. You can easily determine if your separation goals would be possible with this information.

This User Guide will give you the ability to predict where your compounds should elute for acids, bases and neutrals at three different pH.

Octanol/Water Partition Coefficient (Log P) tend to be large for compounds with extended non-polar structures (such as long chain or multi ring hydrocarbons) and small for compounds with highly polar groups. Log P values provide a measure of hydrophilic vs. hydrophobic nature of your compound and relative K' on the Cogent hQ™ C8 Columns.