Van Berkel Gary J, Kertesz Vilmos
Organic and Biological Mass Spectrometry Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6131, USA.
Rapid Commun Mass Spectrom. 2009 May;23(9):1380-6. doi: 10.1002/rcm.4014.
This paper reports on the conversion of a liquid microjunction surface sampling probe (LMJ-SSP) into a two-electrode electrochemical cell using a conductive sample surface and the probe as the two electrodes with an appropriate battery powered circuit. With this LMJ-SSP, two-electrode cell arrangement, tagging of analyte thiol functionalities (in this case peptide cysteine residues) with hydroquinone tags was initiated electrochemically using a hydroquinone-doped solution when the analyte either was initially in solution or was sampled from a surface. Efficient tagging (approximately 90%), at flow rates of 5-10 microL/min, could be achieved for up to at least two cysteines on a peptide. The high tagging efficiency observed was explained with a simple kinetic model. In general, the incorporation of a two-electrode electrochemical cell, or other multiple electrode arrangement, into the LMJ-SSP is expected to add to the versatility of this approach for surface sampling and ionization coupled with mass spectrometric detection.
本文报道了一种利用导电样品表面和探头作为两个电极，并配备合适的电池供电电路，将液体微结表面采样探头（LMJ-SSP）转变为双电极电化学池的方法。使用这种LMJ-SSP和双电极池配置，当分析物最初处于溶液中或从表面采样时，在对苯二酚掺杂溶液存在的情况下，通过电化学方法启动对分析物硫醇官能团（在本文中为肽半胱氨酸残基）进行对苯二酚标记。对于肽上的至少两个半胱氨酸，在流速为5-10微升/分钟时，可以实现高达约90%的高效标记。用一个简单的动力学模型解释了观察到的高标记效率。一般来说，将双电极电化学池或其他多电极配置整合到LMJ-SSP中，有望增加这种表面采样和电离结合质谱检测方法的多功能性。
