Department of Chemistry and Biochemistry University of Texas at Arlington Arlington, Texas 76019-0065, United States.
Anal Chem. 2017 Sep 19;89(18):10063-10070. doi: 10.1021/acs.analchem.7b02808. Epub 2017 Sep 8.
We introduce a novel carbonate-bicarbonate eluent generation system in which CO is introduced using programmable CO pressures across a membrane into a flowing solution of electrodialytically generated high purity KOH. Many different gradient types are possible, including situations where gradients are run both on the [KOH] and the CO pressure. The system is more versatile than current electrodialytic carbonate eluent generators and can easily generate significantly higher eluent concentrations (at least to 40 mM carbonate), paving the way for future higher capacity columns. Demonstrably purer carbonate-bicarbonate eluent systems are possible compared to manually prepared carbonate-bicarbonate eluents and with considerable savings in time. Performance in different modes is examined. The dissolved CO is removed by a carbon dioxide removal device prior to detection. Best case noise levels are within a factor of 2-3 of best case suppressed hydroxide eluent operation. The eluent system allows particular latitude in controlling elution order/time of polyprotic acid analytes. Although CO introduction is possible prior to hydroxide eluent generation, this configuration causes complications because of electroreduction of CO to formate.
我们介绍了一种新型的碳酸盐-碳酸氢盐洗脱液生成系统，该系统通过在膜上可编程的 CO 压力将 CO 引入到电渗析生成的高纯 KOH 流动溶液中。可以实现多种不同的梯度类型，包括在 [KOH] 和 CO 压力上都运行梯度的情况。与当前的电渗析碳酸盐洗脱液发生器相比，该系统更加通用，并且可以轻松地生成更高的洗脱液浓度（至少达到 40mM 碳酸盐），为未来更高容量的色谱柱铺平了道路。与手动制备的碳酸盐-碳酸氢盐洗脱液相比，可以得到明显更纯净的碳酸盐-碳酸氢盐洗脱液系统，并且在时间上有很大的节省。在不同模式下的性能进行了考察。在检测之前，用二氧化碳去除装置去除溶解的 CO。在最佳情况下，噪声水平与最佳情况下抑制的氢氧化物洗脱液操作相差 2-3 倍。该洗脱液系统允许在控制多质子酸分析物的洗脱顺序/时间方面有很大的灵活性。尽管可以在氢氧化物洗脱液生成之前引入 CO，但由于 CO 的电化学还原形成甲酸盐，这种配置会引起一些问题。
