Method of chromatography in which molecules that are negatively charged are selectively released from stationary phase into the positively charged molecules in mobile phase is termed as:Affinity chromatography
Ion exchange chromatography is the chromatography in which molecules are separated on the basis of charge. Ref: Applications of High Performance Liquid Chromatography By Andrew Pryde, Mary T. Gilbe, Pages 50, 53; Biochemistry By Reginald Garrett, Charles M. Grisham, Page 127.
Affinity chromatography
Ion - Exchange chromatography
Adsorbtion chromatography
Size - Exclusion chromatography