High-efficiency separation of niacin (NIA) and nicotinamide (NIC) still faces large challenge up to date. In this work, a stable zirconium-based metal-organic framework (DUT-67) was used to adsorb and separate NIA and NIC in aqueous solutions. The adsorption capacities for NIA and NIC at the concentration ratio of 1:1 were 110.2 mg g(-1) and 11.2 mg g(-1) respectively. Further study indicates that low ratio of NIA/NIC is in favor of the separation. High temperature can restrain the adsorptions of NIA and NIC but promote the separation. Besides, DUT-67 can be well regenerated via a simple method. Mechanism analysis indicates that electrostatic interaction plays a critical role in the separation of these vitamins. (C) 2019 Elsevier Inc. All rights reserved.