Collaborative Research: Applying Ion-Exchange Chromatography-Supercritical Fluid Chromatography to Small Molecule Analysis

在化学系化学测量和成像项目的支持下，分别来自圣路易斯大学和罗文大学的詹姆斯·爱德华兹教授和詹姆斯·格里尼亚斯教授的研究小组正致力于改进对废水污泥和血液等复杂混合物中的化学物质的分析，他们设计了改进的方法，在鉴定和定量之前物理分离成分。该方法采用了一种新型的“绿色化学”技术，减少了对昂贵和潜在有害溶剂的依赖。该团队还设计了一系列样品预处理，旨在提高分离效率和随后的分析。分析的改进将加强对环境和生物现象的测量和理解。该合作将向本科生和研究生介绍复杂的化学系统和表征工具，从而加强对下一代劳动力的培训。小分子和代谢物的分析在很大程度上受到分离系统性能的限制。Edwards和Grinias实验室联合开发的方法能够预先浓缩衍生化的小分子，然后根据分析物结构对其进行色谱解析。具体来说，该方法需要开发一种二维（2D）离子交换超临界流体色谱（IEX-SFC）分离系统。在这种方法中，小分子衍生与一个阳离子芳香标签，允许他们被预先浓缩在一个IEX柱。使用有机溶剂而不是盐来洗脱IEX，使洗脱液与SFC和质谱（MS）兼容。然后，SFC根据亲水性相互作用（尽可能独立于标签）来解析分析物。全口径IEX-SFC系统和毛细管SFC系统都在开发中，具有多方面的梯度（有机溶剂和温度）。此外，一种新的纳米射线界面正在开发中，以方便与sfc相结合的质谱检测。该奖项反映了美国国家科学基金会的法定使命，并通过基金会的知识价值和更广泛的影响审查标准进行了评估，认为值得支持。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, the groups of Professors James Edwards and James Grinias from Saint Louis University and Rowan University, respectively, are working to improve the analysis of chemicals in complex mixtures like wastewater sludge and blood by devising improved methods to physically separate the constituents prior to their identification and quantitation. The approach utilizes a novel "green chemistry" based technique, with reduced dependence on expensive and potentially harmful solvents. The team is also devising a series of sample pretreatments intended to improve both the separation efficiency and the subsequent analysis. The analysis improvements will enhance the measurement and understanding of environmental and biological phenomena. The collaboration is introducing undergraduate and graduate students to complex chemical systems and tools for their characterization, thereby enhancing the training of the next generation of workforce. The analysis of small molecules and metabolites is limited largely by the performance of the separation system. Methods being jointly developed in the Edwards and Grinias laboratories are capable of preconcentrating derivatized small molecules and then chromatographically resolving them based on analyte structure. Specifically, the approach entails development of a two-dimensional (2D) ion exchange-supercritical fluid chromatography (IEX-SFC) separation system. In this approach, small molecules are derivatized with a cationic aromatic tag which allows them to be preconcentrated on an IEX column. Using organic solvent rather than salts to elute off the IEX renders the eluent compatible with SFC and mass spectrometry (MS). The SFC then resolves analytes based on hydrophilic interactions, independent (insofar as possible) of the tag. Both a full-bore IEX-SFC system and a capillary based SFC system are being developed with multi-faceted gradients (organic solvent and temperature). In addition, a novel nanospray interface is being developed to facilitate MS detection coupled to SFC.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.