Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Ecological Chemistry, Neuherberg, Germany.
Electrophoresis. 2010 Jun;31(12):2070-9. doi: 10.1002/elps.200900726.
Free-flow electrophoresis (FFE), a preparative free zone electrophoretic method, was used offline in conjunction with ultrahigh-resolution FT/ion cyclotron resonance -MS to resolve the complexity of Suwannee River fulvic acid (SRFA). Before MS, the FFE separation conditions and the compatibility with ESI were optimized. The constituents in SRFA were effectively separated based on their charge states and sizes. The obtained mass spectra were compared by means of van Krevelen diagrams and the calculated aromaticity indices of the individual constituents were used to describe the distribution of aromatic/unsaturated structures across the FFE-fractionated samples. The consolidated number of ions observed within the individual SRFA fractions were much higher than those of the bulk samples alone, demonstrating extensive ion suppression effects in bulk SRFA likely also operating in the analysis of complex biogeochemical mixtures in flow injection mode. The FFE approach allows for producing sizable amounts of sample from dilute solutions, which can be easily fractionated into dozens of individual samples with the possibility of further in-depth characterization.
自由流电泳（FFE）是一种制备性的自由区电泳方法，离线与超高分辨率傅里叶变换/离子回旋共振-MS 联用，以解析苏万尼河富里酸（SRFA）的复杂性。在 MS 之前，优化了 FFE 分离条件和与 ESI 的兼容性。根据电荷状态和大小，有效地分离了 SRFA 中的成分。通过范·克里夫伦图比较获得的质谱，并使用计算出的各个成分的芳构化指数来描述 FFE 分级样品中芳构/不饱和结构的分布。单个 SRFA 级分中观察到的离子数量比单独的大块样品多得多，这表明在批量 SRFA 分析中可能也存在广泛的离子抑制效应，这种效应也可能存在于流动注射模式下分析复杂的生物地球化学混合物中。FFE 方法允许从稀溶液中产生大量样品，这些样品可以很容易地分成几十个单独的样品，并有进一步进行深入表征的可能。
