摘要
将氧化石墨烯(GO)通过酰胺键键合到氨基硅胶上,进一步将β-环糊精(β-CD)化学键合于GO上,制备了一种新型手性固定相材料,采用IR、SEM、TEM、元素分析和热重分析进行了表征。7种对映体得到不同程度的拆分,同时此固定相表现出典型的亲水作用色谱(HILIC)特征,4种核苷小分子在流动相为甲醇-乙腈-水(45∶45∶10,V/V)时得到分离。通过考察流动相组成、温度、pH值对分析物保留的影响,进一步探讨了该固定相的分离机理。在20~60℃时,温度越低越有利于分析物质分离;加入质子化溶剂甲醇,4种分析物的保留时间显著减弱;pH值的改变影响分析物的质子化程度进而改变与固定相作用力和保留时间。结果表明,此色谱固定相中GO和β-CD在手性拆分中具有协同作用,而在HILIC中分析物的保留归因于混合模式的保留机理,包括亲水作用、静电作用、氢键、π-π堆积作用等。
Graphene oxide(GO)was covalently coupled to the surface of amino silica gel by amide bond.β-Cyclodextrin(β-CD)was further chemically bonded to GO to prepare a novel chiral stationary phase.The resulting material was characterized by Fourier transform-infrared(FT-IR)spectra,scanning electron microscopy(SEM),transmission electron microscopy(TEM),elemental analysis and thermogravimetric analysis(TGA).The separation of seven enantiomers was improved in varying degrees.At the same time,the stationary phase showed typical characteristics of hydrophilic interaction chromatography(HILIC),and four small nucleoside molecules were separated when the mobile phase was methanol-acetonitrile-water(45∶45∶10,V/V)in HILIC mode.In addition,the separation mechanism of the stationary phase was further explored by studying the effects of mobile phase composition,temperature,and pH on the analyte retention.The low temperature was conducive to the separation of analytes at 20-60℃.The addition of protonated solvent methanol significantly decreased retention time of the four analytes.The pH affected the degree of protonation of the analyte,the interaction among analytes and stationary phase,and retention time of analytes.The results showed that GO andβ-CD played a synergistic effect in the chiral resolution of the chromatographic stationary phase.The retention of analytes in HILIC was attributed to their mixed-mode retention mechanisms including hydrophilic interactions,electrostatic interactions,hydrogen bonding,π-πstacking and so on.
作者
李强
李媛媛
朱楠
高柱仙
李添君
周彤
马玉龙
LI Qiang;LI Yuan-Yuan;ZHU Nan;GAO Zhu-Xian;LI Tian-Jun;ZHOU Tong;MA Yu-Long(State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, Ningxia University,Yinchuan 750021,China;College of Chemistry and Chemical Engineering,Ningxia University,Yinchuan 750021,China)
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2018年第9期1455-1463,共9页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金项目(No.21465019)
宁夏高等学校科学研究基金(No.NGY201814)
宁夏回族自治区化学工程与技术国内一流学科项目(No.NXYLXK2017A04)
大学生创新创业训练计划项目(No.201810749090)资助~~
关键词
环糊精
氧化石墨烯
手性固定相
对映体分离
亲水作用色谱
Cyclodextrin
Graphene oxide
Chiral stationary phase
Enantioseparation
Hydrophilic interaction chromatography
