ABSTRACT
Wide-bore capillary hydrodynamic chromatography (W-HDC) resolves analytes on the basis of a difference in the extent of radial diffusion simply by their passage through an empty capillary. The combination of this method with ICP-MS proves efficient for the evaluation of the interaction of metal ions with molecular aggregates. Lecithin vesicles are suitable molecular aggregates for the uptake of the lanthanide ions in the presence of the first row transition metal ions, suggesting that the present method is applicable to the screening of the molecular aggregate system suitable for selective extraction of a particular targeted small molecule. The visual inspection of the elution profiles gives us qualitative but useful information on the interaction between the vesicle and metal ions. In addition, studying the slope of the front edge of an elution curve provides more quantitative implications.
ABSTRACT
Wide-bore hydrodynamic chromatography (HDC) is a very simple method based on the passage of analytes through an open capillary. As shown in previous papers, an analyte, which diffuses over the entire cross-section of a capillary before it is detected, gives a Gaussian-shaped peak; such an analyte is called diffusive. In contrast, an analyte with poor diffusivity gives an asymmetrical peak with the apex at the half time of the peak of a diffusive analyte. Their diffusivity is determined by the diffusion coefficients, dimensions of a capillary, and a flow rate. A consideration of the diffusivity evaluated on the basis of these variables allows us to realize fast wide-bore HDC separation. Sub-second separation is demonstrated using test analytes, such as fluorescein and polystyrene latexes.
