HYDRODYNAMIC CHROMATOGRAPHY IN NARROW AND WIDE-BORES; WHETHER RADIAL DIFFUSION IS ESSENTIAL OR NOT

Abstract

Methodological features of hydrodynamic chromatography (HDC) both in narrow and wide-bores are discussed in this review. HDC in narrow-bore allows separation of particles or macromolecules having relatively large dimensions; whereas, wide-bore HDC (W-HDC) allows separation of even small molecules only if they have one-order different intrinsic diffusivity. Main focus is on the latter method. This method relies on the diffusion of analytes and laminar flow. Since a stable and well-defined laminar flow is established in a capillary, it is a suitable platform of W-HDC. We discuss the basic principles followed by some applications. In addition, the strategy for rapid separation is discussed on the basis of a convenient parameter derived from the advection-diffusion equation. Separation in the sub second range is possible with W-HDC by appropriate reduction of the system dimension.

Keywords:

• diffusion of analytes
• particle separation
• rapid separation
• wide-bore hydrodynamic chromatography