Integrating Accelerated Droplet Chemistry with LC-MS for High Throughput Quantitative Analysis

项目摘要/摘要 越来越需要改进脂类和糖类的特性，以用于临床和 生物医学研究目的。核磁共振是获取有关的详细结构信息的首选方法 糖类。然而，核磁共振通常需要毫克(微摩尔)的分析物；这通常超过 与生物相关的水平。对于脂质，质谱仪(MS)提供了一种快速分析的有效途径， 但是，由于广泛的结构多样性，定量分析在分离感兴趣的物种方面遇到了困难。 提出了一种新的MS方法，从根本上解决了定量和定性MS方面的挑战 通过利用在线加速液滴化学。由于电喷雾电离中的离子抑制效应 多发性硬化发生在液滴形成过程中，我们的方法旨在准确地在 液滴形成点-不是在溶液中加入试剂之前，也不是在执行气相操作之后 反应。这种策略简化了仪器要求，并允许有效地耦合到液体 层析(LC)。选定的基于液滴的反应提高了信噪比，使Femtomole成为可能 灵敏度采用&lt；1微米L样品体积。我们的平台产生的气相离子强度反映了 溶液中相应的分析物浓度。重要的是，选定的基于液滴的反应允许 脂类和糖类有待区分。我们建议将在线液滴反应与LC相结合，以实现高 复杂混合物中脂类和糖类的吞吐量定量。具体研究目标是： 目的1：研制一种用于耦合加速液滴的功能性内容式电喷雾平台 液质联用在糖类分析中的应用提出了一种用于耦合液滴的新型包含-ESI源 LC-MS的化学分析我们的方法将使LC流动相和ESI喷雾溶剂独立 最优化。该正交特征有望允许有效地分离异构体糖(连接， 异构体和位置异构体)。选定的液滴反应将提高糖类的可检测性，并提供 对共洗脱的异构体进行第二层鉴定。将验证LC-Contained-ESI-MS/MS平台 通过高通量的组合研究。 目的2：研制液质联用等离子体-液滴熔融型电喷雾源 脂肪分析。我们建议在我们的LC-Contained-ESI-MS/MS平台上包括蚀刻的二氧化硅毛细管 准确定量所有类型的脂类，包括甘油三酯。预计该设备将启用 瞬时测定不饱和度、C=C键位置和键取向(顺式/反式)。 脂类和糖类定量分析方法的相继发展将导致 伴随而来的是为疾病诊断和高通量分析应用创建通用平台 以有效地指导合成方法的发展。拟议的战略也将在 使用现有仪器进行生物医学研究，无需修改。

Project Summary/Abstract There is an increasing need to improve the characterization of lipids and saccharides for clinical and biomedical research purposes. NMR is the method of choice for obtaining detailed structural information about saccharides. However, NMR typically requires milligram (micromole) quantities of analyte; this often exceeds biologically relevant levels. For lipids, mass spectrometry (MS) provides an efficient avenue for rapid profiling, but quantitative analysis is challenged by difficulty in isolating species of interest due to wide structural diversity. A new MS approach is proposed that fundamentally addresses challenges in quantitative and qualitative MS by utilizing online accelerated droplet chemistry. Since ion suppression effects in electrospray ionization (ESI) MS occur during droplet formation, our method is designed to tackle this intellectual challenge exactly at the point of droplet formation – not before by adding reagents in solution, and not after by performing gas-phase reactions. This strategy simplifies instrumentation requirements and allows effective coupling to liquid chromatography (LC). Selected droplet-based reactions improve signal-to-noise ratios to enable femtomole sensitivity using <1 µL sample volume. Gas-phase ion intensities generated by our platform reflect the corresponding analyte concentration in solution. Importantly, selected droplet-based reactions allow isomers of lipids and saccharides to be differentiated. We propose to couple online droplet reactions with LC to enable high throughput quantification of lipids and saccharides in complex mixtures. The specific research aims are: Aim 1: To develop a functional contained-electrospray platform for coupling accelerated droplet chemistry on LC-MS for saccharide analysis. A novel contained-ESI source is proposed to couple droplet chemistry with LC-MS. Our method will enable LC mobile phase and ESI spray solvent to be independently optimized. This orthogonal feature is expected to allow effective separation of isomeric saccharides (linkage, anomeric, and position isomers). Selected droplet reactions will improve detectability of saccharides and provide a second layer of identification for isomers that co-elute. The LC-contained-ESI-MS/MS platform will be validated via high throughput combinatorial studies. Aim 2: To develop a plasma-droplet fusing contained-electrospray source for coupling LC-MS for lipid analysis. We propose to include etched silica capillaries on our LC-contained-ESI-MS/MS platform for accurate quantification of all types of lipids, including triglycerides. The device is expected to enable instantaneous determination of degree of unsaturation, C=C bond position, and bond orientation (cis/trans). The tandem development of quantitative analytical methods for lipids and saccharides will result in concomitant creation of versatile platforms for applications in diseases diagnosis and high throughput analysis of rare sugars to effectively guide synthetic method development. The proposed strategy will also be valuable in biomedical research using existing instruments without modification.