title: A simple method for the synthesis of a polar-embedded and polar-endcapped reversed-phase chromatographic packing with low activity of residue silanols.
abstract: Octadecyl bonded silica (ODS) is the most popular packing for reversed-phase chromatography. However, it generally demonstrates bad resolution for polar analytes because of the residue silanols and its poor stability in aqueous mobile phase. To address the problem, a new reversed-phase packing containing both polar-embedded and polar-endcapped moieties was proposed. It was prepared by a very simple method, in which the epoxide addition reaction of 3-glycidoxypropyltrimethoxysilane with 1-octadecanethiol proceeded simultaneously with the reaction of silane coupling onto silica particles. By controlling the molecular ratio of 3-glycidoxypropyltrimethoxysilane to 1-octadecanethiol higher than 1.0 (1.56 for the present study), both polar-embedded and polar-endcapped moieties were achieved onto the packing. The performance of the packing was evaluated in detail. The results demonstrated that neutral, acidic and basic analytes were well separated on the packing. The column efficiency for phenanthrene was 34,200 theoretical plates per meter. In addition, four nucleotides can be separated in 100% phosphate buffered saline solution with good reproducibility, which indicates the packing has good stability in aqueous mobile phase. Amitriptyline, a typical basic analytes, was eluted out with relatively symmetric peak shape (asymmetry factor of 1.36), which implies that the packing has not suffered from the negative effect of residue silanols significantly. Good stability in buffer solution of pH ranging from 2.0 to 10.0 was also documented for the packing.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Wuhan University), Ministry of Education, Wuhan 430072, China. Electronic address: liuhaiyan15@sina.cn.
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Liu
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Wuhan University), Ministry of Education, Wuhan 430072, China. Electronic address: 76020463@qq.com.
authors.forename: Zhi-yong
authors.initials: ZY
authors.lastname: Li
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Wuhan University), Ministry of Education, Wuhan 430072, China. Electronic address: kite1977991@sina.com.
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China. Electronic address: 373167239@qq.com.
authors.forename: Ying-wen
authors.initials: YW
authors.lastname: Xue
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Wuhan University), Ministry of Education, Wuhan 430072, China. Electronic address: shizg@whu.edu.cn.
authors.forename: Zhi-guo
authors.initials: ZG
authors.lastname: Shi
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D056148:Chromatography, Reverse-Phase; D015203:Reproducibility of Results; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: C403136:3-glycidoxypropyltrimethoxysilane; D012821:Silanes; D013438:Sulfhydryl Compounds; C082343:silanol; C055360:n-octadecyl mercaptan; D012822:Silicon Dioxide
keywords: High performance liquid chromatography; Polar-embedded; Polar-endcapped; Reversed-phase chromatographic packing