HEAVY CLUSTER IMPACT DESORPTION OF LARGE MOLECULES

拟议研究的长期目标是开发， 制造和销售用于溅射大型、 脆弱的分子。这项新技术被称为大规模星系团撞击 质谱学(MCIMS)，是基于使用大量，多电荷， 有机团簇作为解吸夹带样品离子的主束 在液体基质中。我们建议通过以下方式实现这些目标 一种双极(正或负)大质量团簇离子束源 影响能量/核子在0.01范围内的甘油基质 EV/Amu小于E/N小于1.0 EV/Amu提供极软 溅射完整分子的方法。溅射过程， 受冲击波现象支配，预计将提供增强 二次离子产额显著降低电离和辐射 基质材料的损坏。凭借这些优势，大规模的集群影响 光谱显示较低的化学噪声背景和改进的信噪比 噪波比。除了解吸大的生物分子外，这 新的“软”电离方法应该被证明对质量有利 混合物的光谱分析，溶液相化学的研究和 对解吸过程的基本方面的研究。

The long term objectives of the proposed research are to develop, manufacture and market new instrumentation for the sputtering of large, fragile, molecules. This new technology, called massive cluster impact mass spectrometry(MCIMS), is based on using massive, multiply charged, organic clusters as the primary beam for desorbing sample ions entrained in liquid matrices. We propose to meet these objectives by developing a bipolar (positive or negative) massive cluster ion beam source capable of impacting glycerol matrices with energies/nucleon in the range 0.01 eV/amu less than E/N less than 1.0 eV/amu providing an extremely soft method for sputtering intact molecules. The sputtering process, governed by shock wave phenomenon, is expected to provide enhanced secondary ion yields with significantly reduced ionization and radiation damage of matrix material. With these benefits, massive cluster impact spectra show lower chemical noise background and improved signal-to- noise ratios. In addition to the desorption of large biomolecules, this new "soft" ionization method should prove advantageous for the mass spectral analyses of mixtures, the study of solution phase chemistry and the investigation of fundamental aspects of desorption processes.