Four kinds of protein standards were analyzed using IEC QA-825 (a column for strong anion exchange chromatography). Since the pH value of the eluent is 6.0 and the pI value of conalbumin is in the range of 6.0 to 6.8, the conalbumin cannot be retained by the packing material and therefore it elutes rapidly. The other proteins like transferrin, ovalbumin and trypsin are negatively charged because their pIs are lower than 6.0 and therefore they are retained by the packing material. These proteins are released from the surface of the packing material and elute from the column by gradient elution with increasing salt concentration.


Sample :
1. Conalbumin
2. Transferrin
3. Ovalbumin
4. Trypsin inhibitor

Column       : Shodex IEC QA-825 (8.0 mm I.D. x 75 mm)
Eluent       : (A); 20 mM Piperazine-HCl buffer (pH6.0)
               (B); (A) + 0.5 M NaCl
               Linear gradient: 0 min to 30 min, 100 % (A) to 50 % (B)
Flow rate    : 1.0 mL/min
Detector     : UV (280 nm)
Column temp. : Room temp.