Advanced separation and detection methods for supercritical fluid chromatography

用环境清洁的溶剂取代有机溶剂是一个日益受到关注和研究的领域。超临界流体在这方面有着广泛的应用。它们具有类似气体和液体的性质，可产生显著的溶解和质量传输能力。许多实验室正在处理堆积如山的危险废物和缓慢的样品吞吐量，现在正在使用它们来取代传统的分离和分析方法。超临界二氧化碳因其成本低、相对环境相容性好、临界参数温和等优点而备受青睐。在超临界流体色谱(SFC)中，它被用来在将样品组分减压成气体之前，通过一个柱子将它们分离出来进行分析。通过这种方式，SFC以与气相色谱相似的速度和分离能力结合了液相色谱的溶解能力。然而，超临界二氧化碳是非极性的，除非添加极性改进剂，如甲醇，否则无法很好地溶解和分离极性分子。火焰离子化检测器(FID)因其对有机化合物具有良好的通用响应而在色谱学中得到广泛应用。由于甲醇在FID中产生噪声背景信号，该检测器不能与改进的SFC一起使用。目前，使用改性的超临界二氧化碳分离极性化合物并使用FID或其他新型通用检测器进行检测的能力，将极大地帮助各种使用SFC的实验室监控其过程和产品。经常使用SFC的行业包括制药、石油和聚合物行业，这些行业在加拿大很普遍。我们的研究工作将包括：1.研制一种可在甲醇存在下工作的改进型SFC通用型声学探测器。2.发展新的方法，只使用水(它没有FID响应)和二氧化碳来分离/分析具有FID的极性分析物。3.开发利用短柱SFC-FID方法洗脱无改性剂的极性化合物。4.提出了一种新型的多火焰检测器，用于选择性地检测有机溶剂中的硫和磷分析物。我们将把开发的方法与现有的技术进行比较，并通过分析各种样本进行验证。

Replacing organic solvents with environmentally clean solvents is a growing area of concern and research. Supercritical fluids are widely used in this regard. They have gas and liquid-like properties that yield remarkable solvating and mass transport capabilities. Many laboratories coping with mounting hazardous waste and slow sample throughput are now using them to replace conventional isolation and analysis methods. Supercritical carbon dioxide is very popular due to its low cost, relative environmental compatibility and mild critical parameters. In supercritical fluid chromatography (SFC), it is used to transport sample components through a column that separates them for analysis, before it decompresses into a gas. In this way, SFC unites the dissolving power of liquid chromatography with a speed and separation capability similar to that of gas chromatography. However, supercritical carbon dioxide is non-polar and cannot well dissolve and separate polar molecules unless a polar modifier such as methanol is added. The flame ionization detector (FID) is very widely used in chromatography due to its excellent universal response towards organic compounds. Since methanol creates a noisy background signal in the FID, this detector cannot be used with modified SFC. Presently, the ability to separate polar compounds using modified supercritical carbon dioxide and detect them with the FID, or other novel universal detectors, would greatly assist various laboratories using SFC to monitor their processes and products. Frequent SFC users include the pharmaceutical, petroleum, and polymer industries, which are prevalent in Canada. Our research will: 1. Develop a new universal acoustic detector for modified SFC that can operate in the presence of methanol. 2. Evolve new methods of using only water (it has no FID response) and carbon dioxide to separate/analyze polar analytes with FID. 3. Exploit using short column SFC-FID methods to elute polar compounds without modifiers. And 4. Advance a potential new multiple flame detector for SFC to selectively sense sulfur and phosphorus analytes in organic solvents. We will compare the developed methods with current techniques, and validate them by analyzing various samples.