柱内径对堆积边界法富集重现性的影响

Breadmore提出了一种新型毛细管电泳富集方法（电渗流控制下的逆流等速电泳堆积边界法富集）,可对阴离子实现十万倍在线富集效果。本文以NO3-为模型分子考察了不同内径毛细管柱对该富集重现性的影响。实验发现,使用内径为75μm的毛细管柱时富集重现性极不稳定,富集阶段电流对富集时间的积分面积和NO3-电泳峰面积的RSD（n=10）分别高达6.98%和105.43%,而使用内径为25μm的毛细管柱时富集重现性稳定,富集阶段电流对富集时间的积分面积和NO3-电泳峰面积的RSD（n=7）分别为0.96%和4.43%。实验结果表明这种富集方法的稳定性依赖于富集阶段电流对富集时间的积分面积的重现性,进而依赖于实验中采用的毛细管柱内径的大小尺寸。

The Influence of Capillary Internal Diameter on Reproducibility of Concerntration under Isotachophoretic Stacking

Breadmore proposed a new method called electroosmotic flow controlled counterflow isotachophoretic stacking to complete 100,000-Fold concentration for anions.It was studied that the influence of the internal diameter of capillary used on the concentration reproducibility under electroosmotic flow controlled counterflow isotachophoretic stacking.NO-3 was selected as the example.It was found that the experiment results were very unsteady when 75 μm i.d.capillary was used.The RSD(n=10) of so-called current area and peak area of NO-3 were as high as 6.98% and 105.43%,respectively.However,when using 25 μm i.d.capillary,the steady experiment results can be obtained,and the RSD(n=7) of so-called current area and peak area of NO-3 were reduced to 0.96% and 4.43%,respectively.The experimental results showed that the concentration reproducibility was dependent on the reproducibility of area enclosed by current and the concentration stage,furthermore dependent on the internal diameter of the capillary.