CAPACITOR-BASED INTERFACE FOR MASS SPECTROMETRY

描述（改编自申请人的摘要）：本研究的目标 项目是开发一种超灵敏液相质谱接口，基于 圆柱形电容器电离（CCI）技术，其最近被 在申请人的实验室中开发。 新的CCI接口不 需要在喷嘴周围施加外部电场， 金属针和反电极装置通常用于 电喷雾离子化（ESI）。 将样品液体装入 电容器，而不是主要在喷嘴。 这种带电液体 可以喷射到具有各种压力的空间中， 电条件存在。 新设计将限制电晕放电， 并且将允许人们将离子聚焦去溶剂化装置放置在喷雾附近 尖端，其可以低于大气压力。 这一新设计将 相对于现有的ESI源更好的离子传输效率。 它对溶剂的依赖性更小，对大多数生物活性物质的耐盐性更强。 样品，并将同样工作在积极和消极的离子模式。 像 电喷雾，这种新设备将适用于许多类型的 仪器，包括四极，四极离子阱，傅里叶变换， 观察到的信号/噪声改善 预期生物分子是10至500倍。 生成的初步数据 使用CCI前端，与其他工厂标准Finnigan加热 毛细管界面，表明大约500倍的改善， 负离子注入分析的浓度检测限 在50 nL/min的流速下，将脂质A二磷酸化。 在生物分子的痕量分析中， 难以喷射，或者具有相对高的检测极限， 使用现有的电喷雾技术。 其中包括许多生物 阴离子或在气相中容易形成阴离子的化合物，例如 糖脂、碳水化合物、核酸、酸性蛋白质和酸性蛋白质。 缩氨酸 正离子的分析也有望得到改进 生物起源。

DESCRIPTION (Adapted from the applicant's abstract): The goal of this project is to develop an ultra sensitive liquid phase MS interface, based on the cylindrical capacitor ionization (CCI) technique which has recently been developed in the applicant's laboratory. The new CCI interface does not require an externally applied electric field around the spray tip, such as the metal needle and a counter electrode arrangement normally employed in electrospray ionization (ESI). The sample liquid is charged inside the capacitor instead of primarily at the spray tip. This charged liquid then can be sprayed into a space which may have a variety of pressure and electrical conditions present. The new design will limit corona discharge, and will allow one to put an ion focusing desolvation device near the spray tip, which can be below atmospheric pressure. This new design will have much better ion transmission efficiency relative to existing ESI sources. It will be less solvent dependent and more salt tolerant for most biological samples and will work equally well in positive and negative ion mode. Like electrospray, this new device will be applicable to many types of instruments, including quadrupole, quadrupole ion trap, Fourier transform, and time-of-flight MS. The signal/noise improvements observed for biomolecules are expected to be 10 to 500-fold. Preliminary data generated using a CCI front end, with an otherwise factory standard Finnigan heated capillary interface, indicated roughly a 500-fold improvement in concentration detection limits for the negative ion infusion analysis of diphosphorylated lipid A, at a flow rate of 50 nL/min. The greatest impact on biomedical research will be felt in the trace analysis of biomolecules that are difficult to spray, or that have relatively high detection limits, using existing electrospray technology. This would include many biological anions, or compounds that readily form anions in the gas phase, such as glycolipids, carbohydrates, nucleic acids, acidic proteins and acidic peptides. Improvements are also expected for the analysis of positive ions of biological origin.