title: A comprehensive two-dimensional normal-phase x reversed-phase liquid chromatography based on the modification of mobile phases.
abstract: A comprehensive orthogonal two-dimensional liquid chromatography (2D-LC) based on the modification of mobile phases was developed with a sample loop-valve interface. To improve the compatibility of mobile phases and analysis speed, some special solvents were chosen as the mobile phases, and the column temperature was elevated to decrease the viscosity of mobile phases of reversed-phase liquid chromatography (RPLC). Based on this principle, the first dimension was normal-phase liquid chromatography (NPLC) with a SiO2 column, and the second dimension was reversed-phase liquid chromatography containing two tandem C18 columns. 1,4-Dioxane was used in the NPLC mobile phase, and isopropyl alcohol was employed in the RPLC mobile phase. Moreover, the elevated column temperature enabled the reduction of the backpressure and using tandem C18 columns to improve the resolving power in RPLC. The new comprehensive 2D-LC system and applied strategy offered a novel idea for construction of 2D-LC system. A traditional Chinese medicine, Zhengtian pill, was used as the test sample to evaluate the constructed 2D-LC system. 876 peaks were detected, and the peak capacity reached 1740.
authors.affiliation: School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
authors.forename: Yuanlong
authors.initials: Y
authors.lastname: Wei
authors.forename: Tao
authors.initials: T
authors.lastname: Lan
authors.forename: Tao
authors.initials: T
authors.lastname: Tang
authors.forename: Lingyi
authors.initials: L
authors.lastname: Zhang
authors.forename: Fengyun
authors.initials: F
authors.lastname: Wang
authors.forename: Tong
authors.initials: T
authors.lastname: Li
authors.forename: Yiping
authors.initials: Y
authors.lastname: Du
authors.forename: Weibing
authors.initials: W
authors.lastname: Zhang
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000032:analysis; D008962:Models, Theoretical; D013696:Temperature
chemical_list: D004365:Drugs, Chinese Herbal