全二维气相色谱技术及其进展

 许多分析问题的解决需要得到比一维色谱技术能提供的更高的分辨率。分离能力可通过使用多种分离技术或机理的组合来增强。此时 ,样品被分散在不同的时间维 ,最终的分辨率强烈地依赖于这些维间分离特性的差异。当它们之间没有关联 ,也即相互间正交时 ,系统可获得最高的分辨率。全二维气相色谱 (GC×GC)提供了一个真正的正交分离系统。它把分离机理不同而又互相独立的两支色谱柱以串联方式结合组成二维气相色谱。在这两支色谱柱之间装有的一个调制器起捕集再传送的作用。全二维色谱的峰容量为组成它的两支色谱柱各自峰容量的乘积。

Technique and Advance ofComprehensive Two-Dimensional Gas Chromatography

Many analytical problems require more resolution than the conventional single column chromatographic technique can provide. In such cases the separation power can be enhanced by using more than one separation technique or mechanism. The sample is then dispersed in different time dimensions. The resolution obtained depends strongly on the difference between these dimensions. The highest resolution is gained when there is no correlation between the separations, the dimensions being orthogonal to each other. Comprehensive two-dimensional gas chromatography (GC x GC) provides a true orthogonal separation system in which a modulator serially couples two columns containing dissimilar stationary phases. It focuses and subsequently reinjects components eluting from the first column into the second one. The system generates a peak capacity that is approximately equal to the product of the peak capacities of the two individual separation systems. In this paper, technique and instrumental considerations of GC x GC are discussed. The three designs of contemporary GC x GC systems are presented and compared. A number of typical applications on complex samples such as petroleum products and environmental pollutants are also cited. Finally, the future perspectives of GC x GC are simply discussed.