Advanced Techniques for Organic Analysis

该研究将侧重于综合多维分离领域的进展，包括气相色谱（GCxGC）和液相色谱（LCxLC），以及挥发性有机化合物（VOCs）的被动采样。在多维领域，该研究旨在开发新的方法，从而更有效地分离各种样品，从挥发性化合物到完整的蛋白质。被动采样研究的主要目标是通过数学建模更好地了解采样器，从而为各种基质开发新的/改进的采样器。在GCxGC中，我们将进一步探索第二维（2D）温度编程的开创性概念。目前，所有GCxGC分析都是通过将2D柱保持在恒定温度下进行的，该温度等于或高于主GC烘箱的温度。这不可避免地导致一般洗脱问题。我们已经在初步的开创性工作中表明，2D温度编程导致峰值容量的显着增加。我们将通过在2D中引入适当的温度控制以及减少2D柱的冷却时间来进一步推进这一概念。系统的性能将使用目前市场上可用的所有调制方法进行评估。我们还计划开发一种新的调制器，结合了流量和热调制器的最佳功能，不需要消耗品。 在LCxLC领域，我和我的团队将推动在两个维度上使用类似的分离机制以及平行的移动的相梯度。目前的想法是，二维梯度是必要的，以实现良好的正交性，在LCxLC。我们已经通过初步实验证实，在两个维度上的相关分离机制，平行梯度产生最好的正交性和最高的峰值容量。我和我的团队将在完整蛋白质的分离中测试这一概念，预计这将在生物制药行业中发挥至关重要的作用。我们将寻求通过引入基于热响应固定相的热调制来进一步提高蛋白质的LCxLC分离效率，该热响应固定相的特征在于在高温下的高保留性和在低温下的低保留性。 我的小组开发的基于PDMS的渗透被动采样器被广泛用于表征世界各地的土壤气体，因为它们是唯一的被动土壤气体采样器，允许测定气体中的分析物浓度，而不仅仅是收集的量。我和我的学生开发了一个采样器的数学模型，可以更好地理解其性能。这一初始模型将进一步开发，以探索潜在的新应用，包括从地下水中进行挥发性有机化合物采样。它还将用于指导基于热解吸的新土壤气体采样器的开发。

The research will focus on the advancements in the area of comprehensive multidimensional separations, including gas chromatography (GCxGC) and liquid chromatography (LCxLC), and in passive sampling of volatile organic compounds (VOCs). In the multidimensional realm, the research will aim at developing novel approaches leading to more efficient separations of a variety of samples, from volatile compounds to intact proteins. The main goal of the passive sampling research will be better understanding of the sampler through mathematical modelling, leading to the development of new/improved samplers for a variety of matrices. In GCxGC, we will further explore the pioneering concept of temperature programming of the second dimension (2D). Currently, all GCxGC analyses are carried out by keeping the 2D column at a constant temperature, equal to or higher than that of the main GC oven. This inevitably leads to the general elution problem. We have shown in a preliminary pioneering work that temperature programming in 2D leads to a significant increase in peak capacity. We will further advance this concept by introducing proper temperature control in 2D, as well as reducing the cooling time of the 2D column. The performance of the system will be evaluated using all modulation approaches currently available on the market. We also plan to develop a new modulator combining the best features of flow and thermal modulators and requiring no consumables. In the area of LCxLC, my team and I will promote the use of similar separation mechanisms in both dimensions together with parallel mobile phase gradients. Current thinking is that 2D gradients are necessary to accomplish good orthogonality in LCxLC. We have confirmed through preliminary experiments that with correlated separation mechanisms in both dimensions, parallel gradients produce the best orthogonality and the highest peak capacity. My team and I will test the concept in the separation of intact proteins, which is expected to gain crucial importance in the biopharmaceutical industry. We will seek further improvements in the efficiency of LCxLC separations of proteins through the introduction of thermal modulation based on thermally-responsive stationary phases, characterized by high retentivity at elevated temperatures, and low retentivity at low temperatures. PDMS-based permeation passive samplers developed by my group are being widely used for the characterization of soil gas around the world owing to the fact that they are the only passive soil gas samplers allowing for the determination of analyte concentrations in the gas rather than just the amount collected. My student and I have developed a mathematical model of the sampler allowing better understanding of its performance. This initial model will be developed further to explore potential new applications, including VOC sampling from groundwater. It will also be used to guide the development of a new soil gas sampler based on thermal desorption.