Selective comprehensive multi-dimensional separation for resolution enhancement in high performance liquid chromatography. Part I: Principles and instrumentation

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• 作者：Stephen R. Groskreutz ; Michael M. Swenson ; Laura B. Secor ; Dwight R. Stoll ; ^{dstoll@gustavus.edu}
• 关键词：Two-dimensional ; Multi-dimensional ; HPLC ; Focusing ; Resolving power
• 刊名：Journal of Chromatography A
• 出版年：2012
• 出版时间：9 March, 2012
• 年：2012
• 卷：1228
• 期：Complete
• 页码：31-40
• 全文大小：1056 K

文摘

An approach to enhancing the resolution of select portions of conventional one-dimensional high performance liquid chromatography (HPLC) separations was developed, which we refer to as selective comprehensive two-dimensional HPLC (sLC ¡Á LC). In this first of a series of two papers we describe the principles of this approach, which breaks the long-standing link in on-line multi-dimensional chromatography between the timescales of sampling the first dimension (¹D) separation and the separation of fractions of ¹D effluent in the second dimension. This allows rapid, high-efficiency separations to be used in the first dimension, while still adequately sampling ¹D peaks. Transfer, transient storage, and subsequent second dimension (²D) separations of multiple fractions of a particular ¹D peak produces a two-dimensional chromatogram that reveals the coordinates of the peak in both dimensions of the chromatographic space. Using existing valve technology we find that the approach is repeatable ( % RSD of peak area <1.5 % ), even at very short first dimension sampling times - as low as 1 s. We have also systematically studied the critical influence of the volume and composition of fractions transferred from the first to the second dimension of the sLC ¡Á LC system with reversed-phase columns in both dimensions, and the second dimension operated isocratically. We find that dilution of the transferred fraction, so that it contains 10-20 % less organic solvent than the ²D eluent, generally mitigates the devastating effects of large transfer volumes on ²D performance in this type of system. Several example applications of the sLC ¡Á LC approach are described in the second part of this two-part series. We anticipate that future advances in the valve technology used here will significantly widen the scope of possible applications of the sLC ¡Á LC approach.