层析填料中顽固色素去除的新方法研究

A New Method of Removing Stubborn Pigments from Chromatographic Resin

对纯化工艺中因铁离子污染形成黄褐色的阴离子填料进行了研究。该色素在碱性条件下产生并加重,利用常规方法高盐、表面活性剂均无法清除。作者使用磷酸、醋酸、柠檬酸、盐酸进行测试,发现浓磷酸去除填料色素的能力高于柠檬酸,而浓醋酸和浓盐酸不能明显去除填料色素。基于上述结论,进一步研究磷酸在不同浓度和不同处理时间下对填料中色素的影响。结果发现,随着磷酸浓度的增加,铁离子质量浓度和载量相应增加;然而,随着孵育时间的延长,填料载量虽然相应增加,但是铁离子质量浓度却逐渐降低。由此推断,在磷酸处理填料色素的过程中,随着孵育时间的增加,铁离子可能与填料内腔的多孔结构发生二次吸附,使得溶液中的铁离子逐渐减少。通过数据分析结合颜色比较确定,0.5 mol/L磷酸孵育阴离子填料8.75~11.35 min可以显著去除铁离子带来的顽固色素问题,使得填料载量恢复如初,同时也避免相关杂质污染最终蛋白质产品。本研究的去除层析填料杂质的新方法可为相关生物制品在下游工业化领域中降本增效提供参考。

This study investigated the yellow-brown anion exchange resin formed by ferric ion pollution in the purification process. The pigment is produced and aggravated under alkaline conditions, and cannot be removed by conventional methods such as high salt and surfactants.Phosphoric acid, acetic acid, citric acid and hydrochloric acid were used for testing in this study. It was found that concentrated phosphoric acid could remove resin pigments more effectively than citric acid, while concentrated acetic acid and hydrochloric acid could not. Based on the above conclusions, the effect of phosphoric acid on the pigment in the resin under different concentrations and treatment times was further studied. The results showed that the ferric ion concentration and resin capacity increased with the increase of phosphoric acid concentration, however, prolonging incubation time led to the increase ofresin capacity, but gradually decreased ferric ion concentration.Hence, it was inferred that during the treatment ofresin pigment with phosphoric acid, there was secondary adsorption of iron ions to the porous structure of resin lumen with the increase of incubation time, resulting in the gradual decrease of ferric ions in the solution. Through data analysis in combination with color contrast, it was determined that incubating anion exchange resins with 0.5 mol/L phosphoric acid for 8.75~11.35 minutes could significantly remove the stubborn pigment problems caused by ferric ions, and restored the resin capacity recover, while avoiding related impurities to pollute the final protein product. The new method for removing impurities in chromatography resin studied in this paper could provide a theoretical reference for the cost reduction and efficiency enhancement of related biological products in the downstream industrialization.