Effect of MnCl2 deposition content on the textural properties of activated alumina and its elution performance for hydrogen isotopes

By a solution impregnation method, three modified stationary phases were prepared by contacting activated alumina with MnCl 2 at different MnCl 2 :Al 2 O 3 molar ratios = 1:10, 1:5, 1:2.5, respectively. N 2 sorption isotherms at 78 K were examined for the unmodified and modified samples, from which pore size distributions (PSD) of textural properties were derived with density function theory. Elution chromatographic tests of hydrogen isotopes were carried out at 78 K. The results indicated that both the microporous specific surface area (SSA) and the mesoporous SSA decline after modification, while the microporous SSA remains nearly unvaried among the modified ones. The chromatographic retention times as well as the bandwidths decline as the Mn content rises. The resolution of chromatographic peaks increases after modification, it remains unvaried and then decreases as the Mn content increases. The PSD of alumina SSA changed by the modification significantly influences the hydrogen isotopic elution chromatography.