感应交流电延缓nESI中模拟生物样品引发的毛细管堵塞

Mitigating clogging of nESI with nonvolatile buffers that mimic biological samples by induced alternative voltage

生物样品的检测需要纳升电喷雾离子化质谱(nESI-MS)来适应更苛刻的条件,如高浓度的非挥发性缓冲液和亚微米尺寸的毛细管孔径.以上两个需求会给nESI-MS带来一个棘手的问题:毛细管堵塞.因此,为了延缓毛细管堵塞,我们将感应交流电压施加在尖端内径小于1μm且注入高浓度盐溶液的毛细管上进行电喷雾.结果表明,改进后的毛细管比常规nESI下的毛细管寿命长1~2个数量级.较长的喷雾时间是由于电场方向周期性变化使析出的盐结晶再溶解从而延缓毛细管堵塞.同时,经过长时间(约10 min)高浓度盐溶液的电喷雾,改进后的nESI仍保持稳定和灵敏的信号.最后对模拟细胞外液和细胞内液进行了验证,结果表明感应nESI是一种延缓毛细管堵塞的广泛适用的生物样品分析方法.

The detection of biological samples requires the adaptation of nanoelectrospray ionization mass spectrometry(nESI-MS)to hasher conditions,such as high concentrations nonvolatile buffers and sub-micrometer scale capillary tips.The two above-mentioned requirements would pose a considerable challenge,clogging,to nESI-MS.Herein,to mitigate the clogging problem,an induced alternative voltage was applied on the nanoemitters,which had inner diameter of less than 1μm,with the infusion of a high-concentration salt solution,to induce electrospray ionization.The tips lifetime of the modified nESI was found to be 1~2 orders of magnitude longer than that of conventional nESI.The much longer spray time could be attributed to the re-dissolution effect of salt crystals owing to the periodic change in the electric field direction.Meanwhile,the signal of the modified nESI remained stable and sensitive even after a long run(~10 min)for analysis of high-concentration salt solutions.Finally,the mimic extracellular fluid and intracellular fluid were both evaluated,and the result indicated that the application of an induced alternating current voltage can be a widely applicable method to delay clogging during biological sample analysis.