When 10mM ammonium acetate buffer was used as an eluent, each column showed a good chromatogram. When the ammonium acetate concentration was lowered to 1mM, both ODS columns showed tailing peaks caused by interaction between scopolamine and the residual silanol groups in the column.
On the other hand, polymer based ODP2 HP-4D showed no non-specific adsorption of scopolamine to the media even when the ammonium acetate concentration was lowered. Scopolamine elutes with a sharp peak. As elution time and peak shapes are not affected even if the salt concentration in the eluent is lowered, ODP2 HP columns are suitable for ESI methods (LC/MS) where salt concentration in the eluent affects ion suppression of the sample.
Sample : 5micro-L
Columns : Shodex ODP2 HP-4D (4.6mmID*150mm each)
ODS(A), ODS(B) from other manufacturer (4.6mmID*150mm each)
Eluent : Ammonium acetate buffer(pH7.0)/CH3CN=35/65
Flow rate : 1.0mL/min
Detector : UV(254nm)
Column temp. : 40deg-C