An automated orthogonal two-dimensional liquid chromatograph.
An automated orthogonal two-dimensional liquid chromatograph.
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自动化正交二维液相色谱仪。
DOI：
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发表时间：
2003
影响因子：
7.4
通讯作者：
Yu. B. Zelechonok
中科院分区：
文献类型：
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作者：
C. Venkatramani;Yu. B. Zelechonok
一个简单的方法，二维液相色谱已被开发耦合柱的不同选择性使用12端口，双位阀和标准的HPLC系统。两个色谱柱连接处的阀门可将主色谱柱洗脱液连续、定期取样（进样）到辅助色谱柱上。主要维度的分离与常规HPLC相当，而次要柱分离快速，持续数秒。次级维度的高速分离使得在整个色谱运行过程中能够将初级柱洗脱液精确地采样到次级柱上。人们可能期望以反相模式操作的耦合柱液相色谱系统是强相关的，因此是低效的。然而，通过在主维度中应用溶剂梯度并通过在次维度中逐渐增加溶剂强度（调谐），两个维度之间的无效性或交叉相关性被最小化。在调谐的二维系统中，主柱保留（通常是疏水性）对二级柱保留的影响最小。这使得组分与两种固定相相互作用的细微差异能够主导二级色谱柱保留。峰随机分散在保留平面上，而不是沿着对角线，导致正交分离。峰容量是倍增的，每个组分都有一对独特的保留时间，可以进行阳性鉴别。此外，组分的位置提供了分子性质的两个独立度量。通过在不同的二级柱（ODS-AQ/ODS整体柱、ODS/氨基柱、ODS/氰基柱）上分析由一些芳族胺和非胺制成的测试混合物来评价2D-LC系统。样品组分在二维平面上的相对位置随次级柱的变化而变化显著。在二级色谱柱中，氨基和氰基色谱柱提供了最互补的分离，其中几种组分的保留顺序在二级维度中颠倒。2D-LC系统的理论峰容量为450左右，分离持续30 min。涉及氨基和氰基柱的2D-LC系统导致测试混合物的高速分离，大多数化学成分在几分钟内解决。
A simple approach to two-dimensional liquid chromatography has been developed by coupling columns of different selectivity using a 12-port, dual-position valve and a standard HPLC system. The valve at the junction of the two columns enables continuous, periodic sampling (injection) of the primary column eluent onto the secondary column. The separation in the primary dimension is comparable to conventional HPLC, whereas the secondary column separation is fast, lasting several seconds. The high-speed separation in the secondary dimension enables the primary column eluent to be sampled with fidelity onto the secondary column throughout the chromatographic run. One might expect a coupled column liquid chromatography system operating in reverse-phase mode to be strongly correlated and, hence, inefficient. However, by applying a solvent gradient in the primary dimension and by progressively incrementing the solvent strength in the secondary dimension (tuning), the inefficiency or cross correlation between the two dimensions is minimized. In a tuned two-dimensional system, the influence of primary column retention (usually hydrophobicity) is minimal on secondary column retention. This enables subtle differences in component interaction with the two stationary phases to dominate the secondary column retention. The peaks are randomly dispersed over a retention plane rather than along a diagonal, resulting in an orthogonal separation. The peak capacity is multiplicative, and each component has a unique pair of retention times, enabling positive identification. In addition, the location of the component provides two independent measures of molecular properties. The 2D-LC system was evaluated by analyzing a test mixture made of some aromatic amines and non-amines on different secondary columns (ODS-AQ/ODS monolith, ODS/amino, ODS/cyano). The relative location of sample components in the two-dimensional plane varied significantly with change in secondary column. Among the secondary columns, the amino and cyano columns offered the most complementary separation, with the retention order of several components reversed in the secondary dimension. The theoretical peak capacity of the 2D-LC system was around 450 for a separation lasting 30 min. A 2D-LC system involving amino and cyano columns resulted in a high-speed separation of the test mixture, with most of the chemical components resolved within a few minutes.