Hierarchical CaCO₃ Chromatography: A Stationary Phase Based on Biominerals

Abstract

In biomineralization, acidic macromolecules play important roles for the growth control of crystals through a specific interaction. Inspired by this interaction, we report on an application of the hierarchical structures in CaCO3 biominerals to a stationary phase of chromatography. The separation and purification of acidic small organic molecules are achieved by thin-layer chromatography and flash chromatography using the powder of biominerals as the stationary phase. The unit nanocrystals and their oriented assembly, the hierarchical structure, are suitable for the adsorption site of the target organic molecules and the flow path of the elution solvents, respectively. The separation mode is ascribed to the specific adsorption of the acidic molecules on the crystal face and the coordination of the functional groups to the calcium ions. The results imply that a new family of stationary phase of chromatography can be developed by the fine tuning of hierarchical structures in CaCO3 materials.

Designed nanostructures createdviaphysicochemical switching of the growth mode between single crystals and mesocrystals

“…The peculiar performance of biominerals originates from their hierarchical architectures that are comprised of nanograins aligned in specic directions. 9,[38][39][40][41][42][43] Mesocrystals are basically thought to be formed through particle-mediated self-assembly as a nonclassical crystallization process. 33,34 Rectangular nanoblocks, such as nanocubes and nanocuboids, are accumulated on a substrate by a lateral capillary force [44][45][46][47][48] at the vapor-liquid-solid interface and a depletion force between neighboring particles by the evaporation of a liquid medium.…”

A biomimetic hybrid material consisting of CaCO3 mesoporous microspheres and an alternating copolymer for reversed-phase HPLC

“…These results indicate that CaCO 3 -PMAcO behaved as a reversed-phase mode stationary phase for the separation of naphthalene and alkylbenzenes, while pure CaCO 3 generally works as normal-phase mode stationary phase. 7 The octadecene groups of the CaCO 3 -PMAcO microspheres at the stationary phase to mobile phase interface performed a role identical to the octadecyl groups of ODS, resulting in reversedphase characteristics. During the separation of a mixture of 11 alkylbenzenes, all peaks could be clearly observed with a baseline resolution (peak resolution R s = 1.8-4.2 4 1.5) in the chromatogram (Fig.…”

“…5,6 Paying attention to the hierarchical structure of biominerals to control the distribution of substances, a normal phase chromatography stationary phase based on biopolymer-removed crushed seashells has been developed. 7 Although it was shown that the hierarchical structure of biominerals can be applied to a chromatographic separation material, the functionality of the biopolymer of biominerals like egg shells in terms of controlling substance distribution was not fully used for separation purposes.…”

A hydrophobic adsorbent based on hierarchical porous polymers derived from morphologies of a biomineral

“…The hierarchical structures of biominerals were used as the functional materials themselves, self-templates, and templates in previous studies. [6][7][8][9] For example, CaCO 3 biominerals themselves were applied to an adsorbent of gases and heavy metal ions and a stationary phase of chromatography. 6,7 The silica skeleton of a diatom served as the self-template for the preparation of a silicon hierarchical structure with enhanced electrochemical properties.…”

“…[6][7][8][9] For example, CaCO 3 biominerals themselves were applied to an adsorbent of gases and heavy metal ions and a stationary phase of chromatography. 6,7 The silica skeleton of a diatom served as the self-template for the preparation of a silicon hierarchical structure with enhanced electrochemical properties. 8 While biological resources were used as templates for synthesis and morphology control of inorganic materials, 9,10 the approaches were not fully applied to those of organic materials.…”