一种新型去滞留层HPLC柱的初步验证

Performance evaluation for a new type of removing stagnant layer HPLC column

目的评价色谱柱在除去滞留层后的色谱性能变化,为新型高性能色谱柱的研究提供基础。方法采用自制非金属色谱柱,于色谱柱两端加电后,除去色谱柱固定相上的滞留层,考察加电前、后色谱柱的柱径、柱长、固定相的粒径、流速、柱温等对色谱柱保留时间、理论板数等的影响规律。结果随着色谱柱两端的电场强度升高,保留时间无显著性变化,理论板数升高,半峰宽和对称性改善;随着色谱柱的加长、柱径的增大,达到相同效果所要求的电场强度越高;另一方面,随着电场强度的进一步升高,理论板数因柱內发热而下降,出现一个最佳电场强度的极点,表现出电场强度的提升对固定相表面滞留层的破坏,可改善被分离物质在固定相中的交换,促进了色谱柱效能的提高,但过高的电场强度会造成流动相电解加剧和柱內温度上升,从而导致纵向扩散的影响升高,不利于理论板数的上升。结论首次较系统地验证了电场对滞留层的干扰与柱效能的关系,可为高效色谱柱的研制提供依据。

OBJECTIVE To systematical evaluted the chromatographic performance changes after removing the stagnant layer of HPLC column,futher to provide a basis study for a new type of high performance columns.METHODS A self-made non-metallic column was used,after applying voltage to the two ends of the column,the stagnant layer on the stationary phase of the column was removed.Then the changes of the retention time and the number of theoretical plates were investigated due to the changes of the column diameter,column length,particle size,flow rate and column temperature before and after power-on.RESULTS There was no significant change in retention time with increasing electric field strength at both ends of the column.The number of theoretical plates increased,and both half-width and symmetry were also improved.And with the increasing of the length of the column,the required electric field strength was higher.The wider the column diameter was,the higher the electric field strength required.In addition,as the electric field strength further increased,the number of plates decreased due to the heat in the column,and a pole of the optimum electric field strength appeared.It showed the damage of the electric field strength to the stagnant layer on the surface of the stationary phase,which can improve the exchange of the separated material in the stationary phase and promote the improvement of the efficiency of the column.However,the excessive electric field strength might cause the electrolysis to be intensified and the temperature inside the column to rise,followed by the increase in the effect of stimulating longitudinal diffusion.It was not conducive to the increasement of in the number of plates.CONCLUSION The results of the study have,for the first time,systematically verified the relationship between the interference of the electric field on the stagnant layer and the column efficiency,which can provide a basis for the research and development of the high-efficiency chromatographic columns.