Hu J, Xie C, Tian R, He Z, Zou H. Separation of basic and acidic compounds by capillary electrochromatography using monolithic silica capillary columns with zwitterionic stationary phase. J Sep Sci. 2007 Apr;30(6):891–9. doi: 10.1002/jssc.200600173. PMID: 17536734.
Separation of basic and acidic compounds by capillary electrochromatography using monolithic silica capillary columns with zwitterionic stationary phase