Combined ion exchange and adsorption equilibria of 5′-ribonucleotides on the strong acid cation exchange resin NH-1

Abstract

BACKGROUND 5′‐ribonucleotides including uridine 5′‐monophosphate (UMP), adenosine 5′‐monophosphate (AMP), cytidine 5′‐monophosphate (CMP), and guanosine 5′‐monophosphate (GMP) have been widely used as food additives. Ion exchange is a potential technique to separate 5′‐ribonucleotides. A knowledge of uptake equilibrium on ion exchangers is important for the design and scale‐up of ion exchange processes. The uptake equilibria of 5′‐ribonucleotides and Na+ on the strong acid cation exchange resin NH‐1 were studied experimentally and modelled in binary and multicomponent systems. The uptake mechanism and thermodynamics were also studied. RESULTS A modified Helfferich model was developed combining ion exchange of cations with adsorption of zwitter ions. The model can predict the uptake equilibria of 5′‐ribonucleotides and Na+ successfully in multicomponent systems. The hydrophobicity of bases of 5′‐ribonucleotides determined their relative affinities to the resin. The resin shows the strongest affinity for AMP among 5′‐ribonucleotides. The uptakes of 5′‐ribonucleotides cations is an endothermic and entropy‐driven process. CONCLUSION The equilibrium model proposed is important for simulation and design of the dynamic separation process of 5′‐ribonucleotides. UMP, GMP, and CMP can be separated based on their difference in isoelectric point. AMP and CMP with similar isoelectric point can be separated based on their difference in affinity to the resin. © 2016 Society of Chemical Industry

Design and optimization of JO‐IEX process for highly efficient quaternary separation of 5′‐ribonucleotides

“…In addition, it was surveyed that the adsorption capacity of the three 5′‐ribonucleotides onto the RH‐1 resin increased with increasing temperatures, which demonstrated that the adsorption behaviors of 5′‐ribonucleotides onto the RH‐1 resin were thermonegative. As reported in our previous work, 34 due to its specific chemical structure, UMP was not adsorbed by the strong acid cation exchange resin. Hence, the K H value of UMP was set to zero and the adsorption isotherm of UMP was not investigated in this work.…”

“…The adsorption and ion-exchange equilibrium performances of 5 0 -ribonucleotides on the strongly acid polystyrene cation exchange resin NH-1 have been illuminated in our previous work. 34 According to our research results, both the adsorption and ionexchange were involved in the adsorption process of 5 0 -ribonucleotides on the resin. CMP was adsorbed mainly based on the ion exchange between CMP cations (CMP + ) and the resin.…”

Adsorption Equilibria, Kinetics, and Column Dynamics of L-Tryptophan on Mixed-Mode Resin HD-1

“…The carboxyl groups on resin HD-1 dissociate. The Freundlich( l -Trp ± )-Freundlich( l -Trp + ) adsorption isotherm model-ideal mass action law( l -Trp + ) 26 was used to fit the adsorption isotherm data at pH 3.0 and 4.0, respectively. The fitting results were found to be satisfactory (see Figure 5 d).…”

Separation of Cytidine 5′-Monophosphate and Guanosine 5′-Monophosphate Based on the Hyper-Cross-Linked Resin XDA-1 with pH Gradient Elution

“…K 1 , K 2 , and K 3 are dissociation constants of CMP. The values of the dissociation constants are 10 –0.8 , 10 –4.5 , and 10 –6 , respectively …”

“…Nonpolar and weakly polar resins were used to separate different target compounds based on their differences of hydrophobicity. Due to different bases, the hydrophobicity of CMP and GMP molecules is different significantly . Moreover, their hydrophobicity is affected by the solution pH.…”