The alkali durability test shows that the retention times of each sample and relative theoretical plate numbers (TPN) usingODP2 HP-4D were virtually unchanged even after 500 hours. On the other hand, for ODS (A) retention times of each sample decreased rapidly, reducing TPN after 24 hours, thus showing degradation of the column.

Test condition of alkali durability: 
Eluent       : 10 mM Phosphate buffer(pH12)/CH3CN=45/55
Flow rate    : 0.6 mL/min
Column temp. : 30 °C

Sample : 5 μL
1. Pyridine 200 mg/L
2. Phenol 430 mg/L




* TPN before flowing alkali eluent is set as 100% in this test.
 

Column       : Shodex ODP2 HP-4D (4.6 mm I.D. x 150 mm)
               ODS(A) from other manufacturer (4.6 mm I.D. x 150 mm)
Eluent       : H2O/CH3OH=70/30
Flow rate    : 1.0 mL/min
Detector     : UV (254 nm)
Column temp. : 40 °C