When testing the repeatability of Asahipak ODP-50 4E, a polymer-based column for reversed phase chromatography, under alkaline condition, azithromycin was injected repeatedly according toUSP 39 method. When theoretical plate number for azithromycin and resolution of azithromycin/azaerythromycin A regarding number of injections were measured, theoretical plate number and resolution were not changed after 3,000 injections. It was confirmed that ODP-50 4E is very alkaline-resistant.
Sample : 0.5mg/mL each, 10 µL
1 Azaerythromycin A
dissolved in 6.7g/L Dibasic potassium phosphate aq. (pH8.0 adjusted with phosphoric acid)/CH3CN=40/60
Column : Shodex Asahipak ODP-50 4E (4.6mmI.D. x 250mm) Eluent : 6.7g/L Dibasic potassium phosphate aq. (pH11.0 adjusted with 10M KOH) /CH3CN=40/60 Flow rate : 1.0mL/min Detector : UV(210nm) Column temp. : 40°C