Basic Drugs : Effects of Ion Concentration

Effects of ion concentration on elution pattern for the analysis of scopolamine which has tertiary amine and whose pKa is 7.6 is shown. When the ion concentration is lowered, non-specific adsorption is observed for ODS-A and sample is completely adsorbed at the ion concentration lower than 10 mM. This tendency is also observed even for ODS-C which is a polymer-coated ODS column and sample is completely adsorbed at 0 mM. To the contrary, Asahipak ODP columns are free from the non-specific adsorption problem at any ion concentration level. Then ODP columns are suitable for analysis with the ESI method (LC/MS) in which ionization of sample is often supressed under high-salt concentration.

Sample : 1.0 mg/mL Scopolamine , 50 μL

Columns      : Shodex Asahipak ODP-50 4D (4.6 mm I.D. x 150 mm),
               ODS-A, ODS-C (4.6 mm I.D. x 150 mm each)
Eluent       : Phosphate buffer (pH7)/CH3CN=60/40
Flow rate    : 0.6 mL/min
Detector     : UV (254 nm)
Column temp. : 30 °C

Sample Name Index

Operation Manual / Certificate of Analysis

Operation Manuals and Certificate of Analysis / Inspection Certificate for the following products can be downloaded here.

Product Name Index


Applications (Related Information)