Quantitative evaluation of reversed-phase packing material based on calcium carbonate microspheres modified with an alternating copolymer

Kogi Kaizu, Mai Mochida, Hiroaki Imai, Daniel Citterio, Yuki Hiruta

Research output: Contribution to journalArticlepeer-review

Abstract

Considering the vulnerability of silica gel to alkaline mobile phases, a highly alkaline stable stationary phase for HPLC is required to separate basic compounds with high separation efficiency. To address this issue, we have developed a high alkaline stable packing material (CaCO3-PMAcO) based on mesoporous calcium carbonate microspheres modified with poly(maleic acid-alt-1-octadecene). In this study, we report further investigation of the separation performance of CaCO3-PMAcO column by systematically evaluating the effects of particle size and chromatographic conditions. Based on the theory of the van Deemter equation, the separation efficiency was related to the size of CaCO3-PMAcO particles (2.9 – 5.7 µm). The evaluation of thermodynamics of retention by changing the column temperature from 20 °C to 45 °C implied that the retention mode was dominated by hydrophobic interaction associated with the exothermic enthalpy changes (-11.1 to -12.5 kJ/mol). The results of column selectivity tests revealed that the CaCO3-PMAcO column had hydrophobic selectivity comparable to C18 silica gel columns (αP/B; CaCO3-PMAcO column: 1.53, C18 column: 1.69), and higher shape/steric selectivity (αTri/Ter; CaCO3-PMAcO column: 1.56, C18 column: 0.955). In practice, the CaCO3-PMAcO column could be applied to the separation of not only alkylbenzenes and polycyclic aromatic hydrocarbons, but also to basic tricyclic antidepressants by using an alkaline mobile phase (pH 12).

Original languageEnglish
Article number463294
JournalJournal of Chromatography A
Volume1677
DOIs
Publication statusPublished - 2022 Aug 16

Keywords

  • Alkali resistance
  • Alternating copolymer
  • Basic drug
  • Calcium carbonate
  • Reversed-phase chromatography

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Organic Chemistry

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