Flow Field Thermal Gradient Gas Chromatography
Flow Field Thermal Gradient Gas Chromatography
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DOI：
10.1021/acs.analchem.5b02227
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发表时间：
2015-09-01
影响因子：
7.4
通讯作者：
Leppert, Jan
中科院分区：
文献类型：
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作者：
Boeker, Peter;Leppert, Jan
沿气相色谱分离柱的负温度梯度可以最大限度地提高气相色谱的峰聚焦分离能力，也可以降低洗脱温度。不幸的是，到目前为止，在几米长的分离柱上实现平滑的热梯度只能通过昂贵而复杂的人工设置来实现。在这里，我们描述了一种简单而灵活的方法，用于使用标准和易于交换的分离柱产生负热梯度。用第一个原型进行的测量揭示了优化分离过程的新特性。负的热梯度和温度规划的叠加导致组件的准平行分离，每个组件同时在其降低的比平衡温度附近通过柱。因此，这种梯度分离工艺更适合于热不稳定的分子，如炸药和天然或香气成分。高温气相色谱法也受益于降低洗脱温度。即使对于短列，也可以获得非常高的峰值容量。此外，梯度分离是特别有利于非常快速的分离低于1毫米的总保留时间。对炸药的快速测量证明了使用负热梯度的好处。新概念可以大大缩短高分辨率气相色谱的周期时间，并且可以集成到连字或综合气相色谱装置中。
Negative temperature gradients along the gas chromatographic separation column can maximize the separation capabilities for gas chromatography by peak focusing and also lead to lower elution temperatures. Unfortunately, so far a smooth thermal gradient over a several meters long separation column could only be realized by costly and complicated manual setups. Here we describe a simple, yet flexible method for the generation of negative thermal gradients using standard and easily exchangeable separation columns. The measurements made with a first prototype reveal promising new properties of the optimized separation process. The negative thermal gradient and the superposition of temperature programming result in a quasi-parallel separation of components each moving simultaneously near their lowered specific equilibrium temperatures through the column. Therefore, this gradient separation process is better suited for thermally labile molecules such as explosives and natural or aroma components. High-temperature GC methods also benefit from reduced elution temperatures. Even for short columns very high peak capacities can be obtained. In addition, the gradient separation is particularly beneficial for very fast separations below 1 mm overall retention time. Very fast measurements of explosives prove the benefits of using negative thermal gradients. The new concept can greatly reduce the cycle time of high-resolution gas chromatography and can be integrated into hyphenated or comprehensive gas chromatography setups.