Development and Characterization of femto Electrospray Ionization

在国家科学基金会化学部化学测量和成像项目的支持下，以及刺激竞争性研究的既定项目的部分共同资助下，新罕布什尔州（UNH）大学的Anyin Li教授的小组正在探索电喷雾电离质谱的基本过程-用于表征有机，生物，和生化系统，包括药物发现和质量控制。正在制定的方法旨在改进分析优值，为解决基本问题以及加强联合国总部与当地工业和教育合作伙伴的互动提供新的机会。研究活动培训研究生，本科生和高中生，从而增加人才库，以建立更强大的STEM劳动力。K-12科学教师参与制作当代科学教材，以吸引学生的兴趣。该研究小组还举办夏季讲习班，以广泛传播科学和技术。现有的电喷雾电离（ESI）方法的起始电离电流为纳安量级，远高于大多数质量分析仪所需的电流。它们经常受到不均匀的电离效率，非特异性加合物的形成和（对于小发射体）堵塞的困扰。为了解决这些问题，Li团队正在推进和表征飞秒安培范围内的ESI，其流速为皮升/分钟。所开发的方法可以将线性动态范围扩展到更低和更高的浓度，同时提高光谱质量，减少基质干扰和电离效率的变化。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

With support from the Chemical Measurement and Imaging program in the National Science Foundation Division of Chemistry, and partial co-funding from the Established Program to Stimulate Competitive Research, Professor Anyin Li’s group at the University of New Hampshire (UNH) is exploring the fundamental processes underlying electrospray ionization mass spectrometry - one of the most important analytical methods used for characterization of organic, biological, and biochemical systems, including drug discovery and quality control. The methods being developed target improved analytical figures of merit, providing new opportunities to solve fundamental problems as well as to enhance UNH’s interaction with local industry and education partners. The research activities train graduate, undergraduate, and high school students, thereby increasing the talent pool for a stronger STEM workforce. K-12 science teacher participation produces contemporary science teaching materials to engage student interest. The research group is also hosting summer workshops for broad dissemination of science and technology.Existing electrospray ionization (ESI) methods have onset ionization currents on the order of nanoamps, much higher than needed by most mass analyzers. They are often plagued by non-uniform ionization efficiency, formation of nonspecific adducts, and (for small emitters) clogging. To address these issues, the Li group is advancing and characterizing ESI in the femtoamp range, with flow rates on the order of picoliters/minute. The developed methods can extend the linear dynamic range to both lower and higher concentrations, while improving spectral quality and reducing matrix interferences and variations in ionization efficiency.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.