新型亲水整体柱的制备及其在毛细管液相色谱和加压电色谱中的应用

以N,N-二甲基-N-甲基丙烯酰胺基丙基-N,N-二甲基-N-丙烷磺酸内盐(SPP)为单体,季戊四醇三丙烯酸酯(PETA)为交联剂,偶氮二异丁腈(AIBN)为引发剂及两类不同的致孔剂(乙醇/乙二醇和甲醇/1,4-丁二醇)制备了两种新型亲水性整体柱。为了获得理想的柱效、电渗流速度和渗透性,对制备整体柱的各反应物配比进行了研究和优化。比较了两种整体柱在渗透性和分离样品方面的性能,结果表明,以乙醇/乙二醇为致孔剂制备的整体柱在柱效、分离度方面优于以甲醇/1,4-丁二醇为致孔剂制备的整体柱,但在渗透性方面不及后者。探讨了流动相中盐浓度对核苷类样品保留的影响,发现当甲酸铵浓度从10 mmol/L增加到70 mmol/L时,核苷样品的保留因子呈现先增加后减小的状态。将制备的整体柱用于毛细管液相色谱和加压电色谱分别分离胺类、酚类和核苷类样品,获得了理想的分离效果。在分离酚类和核苷类混合样品时,发现加压毛细管电色谱在分离度和分离速度上均优于毛细管液相色谱。     

新型有机-无机杂化整体柱的制备及其在毛细管液相色谱及加压毛细管电色谱中的应用

以丙烯酰胺(AM)为单体,八乙烯基倍半硅氧烷(POSS)为交联剂,偶氮二异丁腈(AIBN)为引发剂,四氢呋喃(THF)为致孔剂,通过原位聚合法制备了poly(POSS-co-AM)有机-无机杂化整体柱,并对各反应物的配比进行了优化。结果表明,当功能单体与致孔剂、POSS与AM的质量比均为1.0: 5.0, AIBN的质量分数为0.1%时,杂化整体柱的柱效最高。无机材料的引入使整体柱结构均匀并具有良好的渗透性,该整体柱既能用于亲水色谱模式,也能用于反相色谱模式。将制备的整体柱用于毛细管液相色谱和加压毛细管电色谱分离核苷类、胺类、硝基苯胺类等化合物,获得了良好的效果。     

混合模式毛细管聚合物整体柱的制备及应用

混合模式毛细管整体色谱柱由于保留机理多样,具有很好的应用前景。本文以[2-（甲基丙烯酰基氧基）乙基]二甲基-（3-磺酸丙基）氢氧化铵（SPE）为单体,乙二醇二甲基丙烯酸酯（EDMA）为交联剂,偶氮二异丁腈（AIBN）为引发剂,正丙醇/1,4-丁二醇/水三元体系为致孔剂,制备了聚合物基质SPE-co-EDMA毛细管液相色谱整体柱。通过系统优化致孔剂和反应物种类和配比、引发剂的用量、反应时间和反应温度等因素,提高了整体柱的柱效、机械强度、渗透性和重复性。结果表明该毛细管整体柱在10 MPa内具有良好的机械强度,渗透性为2.17×10^-14 m²,而且批次内和批次间峰面积的重现性（RSD）分别为1.0%和4.6%。以极性和非极性的多种化合物评价了该毛细管整体柱的色谱性能,结果表明该柱在高有机相中具有亲水相互作用机理,在低有机相中具有反相作用机理,显示出混合模式分离特性。     

以二甲亚砜/正十二醇为二元致孔剂的新型苯乙烯-二乙烯苯毛细管整体柱的制备与表征

首次以二甲亚砜/正十二醇为二元致孔剂,苯乙烯为单体,二乙烯苯为交联剂,过氧化苯甲酰为引发剂,通过原位聚合反应制备了苯乙烯-二乙烯苯聚合物型毛细管整体柱。结果表明,苯乙烯∶二乙烯苯∶二甲亚砜∶正十二醇的体积比为18.7∶15.3∶13.2∶52.8,即二甲亚砜占致孔剂的比例为20%,交联度为45%,致孔剂含量为66%为最优配比。所合成的整体柱实现了反相色谱模式下对小分子苯系物与生物大分子蛋白的快速分离。其中蛋白分离实验的流速达到104μL·min-1,线速度约为12 mm·s-1,而常规色谱柱的线速度为1~2 mm·s-1。该整体柱的渗透性好,可用于物质的高速分离,若对其进行化学修饰,有望用于其它色谱分离模式。     

阳离子交换毛细管整体柱的制备及其在毛细管离子色谱中的应用

以甲基丙烯酸缩水甘油酯(GMA)为功能单体,亚乙基二甲基丙烯酸酯(EDMA)为交联剂,偶氮二异丁腈(AIBN)为自由基引发剂,在三元致孔剂(正丙醇,1,4-丁二醇,水)的存在下,在320!m内径的弹性石英毛细管柱内制备得到带有环氧功能基团的聚合物整体柱基质;利用Na2SO3对其改性,制备得到磺酸基型阳离子交换毛细管整体柱。采用微流泵、毛细管检测池和紫外检测器构建了毛细管离子色谱系统,并对所制备的整体柱的流体力学参数、色谱性能参数进行评价;采用流速梯度洗脱的方式实现9种常见阳离子(Li+,Na+,NH4+,K+,Cs+,Mg2+,Ca2+,Sr2+,Ba2+)的分离分析;此色谱系统还可应用于牛奶中阳离子和三聚氰胺的分离检测。     

毛细管电色谱硅胶整体柱的制备与性能研究

以甲基丙烯酸丙酯基三甲氧基硅烷(MPTMS)为单体,甲苯为致孔剂,偶氮二异丁腈(AIBN)为引发剂,盐酸为催化剂,采用热引发法制备毛细管电色谱硅胶整体柱.在反相毛细管电色谱条件下,对中性化合物硫脲,苯,萘,芴,蒽实现了基线分离了.柱效超过100,000 plates/m.探讨了该柱的制备条件如单体比例,毛细管内径,制柱反应时间对分离的影响,并且在电色谱条件下考察了有机溶剂比例,pH值,电压和温度对分离的影响.     

聚(4-乙烯基苯硼酸-季戊四醇三丙烯酸酯)亲和整体柱的制备与应用

以4-乙烯基苯硼酸为单体,季戊四醇三丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,乙二醇和二甘醇为致孔剂,经原位聚合制备了聚(4-乙烯基苯硼酸-季戊四醇三丙烯酸酯)毛细管整体柱.以单体、交联剂、致孔剂和引发剂的用量为4种因素,最大吸附量、柱效和保留时间为3个考察标准,利用实验设计软件(DOE)优化了其合成条件,验证了正交实验最优结果,得到了整体柱合成的最佳配比为单体7.32 mg,交联剂6 mg,致孔L剂100 μL,引发剂1 mg.在最佳条件下合成整体柱,并进行表征,在微径液相色谱(μHPLC)和加压毛细管电色谱(pCEC)实验中考察了分离特性.结果表明,整体柱固定相表面的硼酸基团在碱性条件下能特异性吸附邻苯二酚、腺苷等含有邻二羟基结构的化合物,具有亲和色谱的特性;同时由于交联剂的性质使其具有反相分离机理,在含有20％有机相的条件下能够将极性不同的苯系物分开.     

磺酸甜菜碱型两性离子亲水毛细管整体柱制备及应用

以3-[N,N-二甲基-[2-(2-甲基丙-2-烯酰氧基)乙基]铵]丙烷-1-磺酸内盐(SPE)为功能单体,季戊四醇三丙烯酸酯(PETA)为交联剂,环己醇和乙二醇(EG)为致孔剂,通过原位聚合法制备磺酸甜菜碱型两性离子亲水毛细管整体柱。优化单体、交联剂和致孔剂的比例等因素,考察了不同SPE含量对整体柱性能和选择性的影响。在最优制备条件下,以苯酚类化合物、烷基苯类化合物和苯甲酸类化合物为分离对象,评价该整体柱的色谱性能以及分离机理。在不同的色谱条件下,该整体柱具有亲水、疏水以及离子交换作用。此整体柱在0.05 m L/min的流速下(线速度为0.265 mm/s)分离烷基苯类化合物时,柱效高达41000~56000 plates/m,该整体柱重现性良好,连续运行的重现性(RSD)低于1.2%。在亲水/离子交换色谱模式下,该整体柱可应用于核苷和碱基的高效分离。     

牛血清白蛋白修饰毛细管整体柱的制备及组氨酸对映体分离

以甲基丙烯酸缩水甘油酯为单体, 乙二醇二甲基丙烯酸酯为交联剂, 环己醇和正十二醇混合溶液为致孔剂, 在最佳聚合条件下, 以偶氮二异丁腈为引发剂, 制备了毛细管整体柱基质, 并且研究了单体、交联剂及致孔剂对整体柱基质孔结构及渗透性的影响; 使用Epoxy方法在基质表面键合BSA, 制得BSA修饰的毛细管整体柱. 将此毛细管整体柱应用于毛细管电色谱中, 成功地分离出了组氨酸对映体, 分离度良好.     

辛基型毛细管液相色谱整体柱的制备、表征及评价

本研究采用以甲基丙烯酸辛酯为单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,正丙醇、1,4丁二醇和水三元混合物为共溶剂,制备了内径为0．53mm的毛细管整体柱材料。详细考察了单体／交联剂比例、单体混合物与致孔剂之间的比例,对所制得材料的通透性、孔径分布、粒度大小等性能的影响;应用包括扫描电镜和压汞法对其进行表征;在毛细管液相色谱(c—HPLC)操作模式进行了初步色谱评价,结果表明：所制得的整体柱具有优良的通透性能,可在高达100μL／min的流速下进行快速分离,同时在离子对模式下对3种金属离子进行了分离,取得了较理想的效果。     

反相毛细管整体柱的制备及其在多肽混合物分离中的应用

采用甲基丙烯酸月桂酯为基础功能单体,乙二醇二甲基丙烯酸酯为交联剂,正十二醇、1,4-丁二醇及二甲基亚砜为致孔剂,在内径为75 μm的石英毛细管内制备了具有良好机械性能及化学稳定性的反相毛细管整体柱。考察了致孔剂的种类、比例以及交联剂在单体混合物中的比例对柱压和分离效果的影响;以单体15%、交联剂15%、致孔剂70%(均为质量分数)作为优化配方,在70 ℃条件下反应24 h;并对所合成的毛细管整体柱进行了电镜表征,测试了流速、柱长与柱压的关系。结果表明,毛细管整体柱的通透性良好,可通过延长柱长的方法提高分离效果。将所制备的毛细管整体柱装于纳升级高效液相色谱仪上进行牛血清白蛋白及血浆样本的胰蛋白酶酶切液的分离,获得了比较理想的分离效果。     

微波聚合快速制备分子印迹毛细管电色谱整体柱

以甲基丙烯酸为功能单体、己二醇二甲基丙烯酸酯为交联剂、 对羟基苯甲酸为模板分子, 采用微波辐射聚合的方式快速制备了分子印迹毛细管电色谱整体柱, 并取得了较好的印迹效果. 分子印迹材料的原位制备5 min即可完成, 大大快于国内外传统的方法.     

Preparation of phosphorylcholine‐based hydrophilic monolithic column and application for analysis of drug‐related impurities with capillary electrochromatography

A hydrophilic monolithic CEC column was prepared by thermal copolymerization of zwitterionic monomer 2‐methacryloyloxyethyl phosphorylcholine (MPC), pentaerythritol triacrylate (PETA), either methacrylatoethyl trimethyl ammonium chloride (META) or sodium 2‐methylpropene‐1‐sulfonate (MPS) in a polar binary porogen consisting of methanol and THF. A typical hydrophilic interaction LC retention mechanism was observed for low‐molecular weight polar compounds including amides, nucleotides, and nucleosides in the separation mode of hydrophilic interaction CEC, when high content of ACN (>60%) was used as the mobile phase. The effect of the electrostatic interaction between the analytes and the stationary phase was found to be negligible. The poly(MPC‐co‐PETA‐co‐META or MPS) monolithic columns have an average column efficiency of 40 000 plates/m and displayed with a satisfactory repeatability in terms of migration time and peak areas. Finally, the column was successfully applied to determine the impurities of a positively charged drug pramipexole which are often separated by ion pair RP chromatography due to their high hydrophilicity. All four components can be baseline separated within 5 min with BGE consisting of ACN/20 mM ammonium formate buffer (pH 3.0; 80/20).     

Preparation of a mixed-mode hydrophilic interaction/anion-exchange polymeric monolithic stationary phase for capillary liquid chromatography of polar analytes

A novel cationic hydrophilic interaction monolithic stationary phase based on the copolymerization of 2-(methacryloyloxy)ethyltrimethylammonium methyl sulfate (META) and pentaerythritol triacrylate (PETA) in a binary porogenic solvent consisting of cyclohexanol/ethylene glycol was designed for performing capillary liquid chromatography. While META functioned as both the ion-exchange sites and polar ligand provider, the PETA, a trivinyl monomer, was introduced as cross-linker. The monolithic stationary phases with different properties were easily prepared by adjusting the amount of META in the polymerization solution as well as the composition of the porogenic solvent. The hydrophilicity of the monolith increased with increasing content of META in the polymerization mixture. A typical hydrophilic interaction chromatography mechanism was observed when the content of acetonitrile in the mobile phase was higher than 20%. The poly(META-co-PETA) monolith showed very good selectivity for neutral, basic and acidic polar analytes. For polar-charged analytes, both hydrophilic interaction and electrostatic interaction contributed to their retention. Peak tailing of basic compounds was avoided and the efficient separation of benzoic acid derivatives was obtained.     

Preparation and evaluation of a neutral methacrylate-based monolithic column for hydrophilic interaction stationary phase by pressurized capillary electrochromatography

A polar and neutral polymethacrylate-based monolithic column was evaluated as a hydrophilic interaction capillary electrochromatography (HI-CEC) stationary phase with small polar–neutral or charged solutes. The polar sites on the surface of the monolithic solid phase responsible for hydrophilic interactions were provided from the hydroxy and ester groups on the surface of the monolithic stationary phase. These polar functionalities also attract ions from the mobile phase and impart the monolithic solid phase with a given zeta potential to generate electro-osmotic flow (EOF). The monolith was prepared by in situ copolymerization of a neutral monomer 2-hydroxyethyl methacrylate (HEMA) and a polar cross-linker with hydroxy group, pentaerythritol triacrylate (PETA), in the presence of a binary porogenic solvent consisting cyclohexanol and dodecanol. A typical HI-CEC mechanism was observed on the neutral polar stationary phase for both neutral and charged analytes. The composition of the polymerization mixture was systematically altered and optimized by altering the amount of HEMA in the polymerization solution as well as the composition of the porogenic solvent. The monoliths were tested in the pCEC mode. The resulting monoliths had different characteristics of hydrophilicity, column permeability, and efficiency. The effects of pH, salt concentration, and organic solvent content on the EOF velocity and the separation of nucleic acids and nucleosides on the optimized monolithic column were investigated. The optimized monolithic column resulted in good separation and with greater than 140,000 theoretical plates/m for pCEC.