5′-ribonucleotides including adenosine 5′-monophosphate (AMP), cytidine 5′-monophsphate (CMP), guanosine 5′-monophosphate (GMP) and uridine 5′-monophosphate (UMP) have been widely used in the food and pharmaceutical industries. This work focused on the assessment of mass transfer process and separation mechanism of four 5′-ribonucleotides and counter-ion Na⁺ on the strong cation exchange resin NH-1. The intraparticle diffusion was determined as the rate-limiting step for the mass transfer of AMP, CMP, GMP, and Na⁺ on the resin NH-1 through the Boyd model. Meanwhile, a homogeneous surface diffusion model (HSDM) combing ion exchange and physical adsorption was proposed and tested against adsorption kinetic data in the batch adsorption systems. The fixed-bed film-surface diffusion model based on the HSDM was then developed and successfully predicted the concentration profiles of 5′-ribonucleotides and the change of pH at the outlet of the fixed-bed in the dynamic adsorption and separation process. Finally, the separation mechanism of 5′-ribonucleotides was presented combining model prediction and experimental results. The separation of UMP, GMP and CMP were mainly based on their differences in isoelectric points, while that of AMP and CMP were lied with the discrepancy of their physical adsorption binding capacity with the resin NH-1.

5'-核糖核苷酸包括腺苷5'-单磷酸盐（AMP），胞苷5'-单磷酸盐（CMP），鸟苷5'-单磷酸盐（GMP）和尿苷5'-单磷酸盐（UMP）已广泛用于食品和制药行业。这项工作的重点是评估强阳离子交换树脂NH-1上四个5'-核糖核苷酸和抗衡离子Na ⁺的传质过程和分离机理。粒子内扩散被确定为AMP，CMP，GMP和Na ⁺传质的限速步骤通过Boyd模型在树脂NH-1上 同时，提出了结合离子交换和物理吸附的均质表面扩散模型（HSDM），并针对间歇吸附系统中的吸附动力学数据进行了测试。建立了基于HSDM的固定床膜表面扩散模型，并成功地预测了5'-核糖核苷酸的浓度分布和动态吸附分离过程中固定床出口pH的变化。最后，结合模型预测和实验结果，提出了5'-核糖核苷酸的分离机理。UMP，GMP和CMP的分离主要是基于等电点的差异，而AMP和CMP的分离是由于它们与树脂NH-1的物理吸附结合能力不同。