ATRP技术制备Sil-LMA反相作用色谱固定相及其性能研究

以5μm大孔硅胶为基质,CuBr/Bpy为催化体系,采用原子转移自由基聚合(Atom transfer radical polymerization,ATRP)技术将甲基丙烯酸月桂酯(LMA)键合到硅胶表面,制得Sil-LMA反相作用色谱固定相。采用元素分析对该固定相进行表征,以芳香族化合物为溶质,甲醇-水为流动相,对该键合相的疏水选择性进行了考察。详细研究了甲醇浓度和温度对溶质保留行为的影响,以胺类、酚类化合物为溶质,评价了其色谱性能,并计算了溶质保留过程的热力学参数。经元素分析测得该填料的接枝量高达2.323 3 mg/m2。实验结果表明,在反相模式下该固定相可基线分离5种胺类化合物和5种酚类化合物。与C18反相柱相比,该合成柱的分离时间缩短且分离效果较好。该固定相具有很好的反相色谱性能,符合反相保留机理。     

奎宁功能化聚乙烯咪唑修饰硅胶亲水相互作用色谱固定相的制备及应用

通过表面自由基链转移聚合和亲核取代反应制备了一种新型奎宁功能化聚乙烯咪唑修饰硅胶亲水色谱固定相(Sil-PIm-Qn)。通过元素分析和红外光谱对该固定相进行表征,并在亲水相互作用色谱(HILIC)模式下对其进行了色谱性能评价。结果表明,该固定相对5种氨基酸、9种磺胺以及10种碱基核苷有较好的分离选择性。实验考察了流动相中有机相乙腈体积分数和水相中乙酸铵浓度对待分离物质保留行为的影响,并进一步对固定相分离的重复性进行了考察,其保留时间的相对标准偏差(RSD)为0.08%~2.30%(n=10)。该亲水色谱固定相制备方法简单,并且表现出了优异的亲水色谱分离性能,有望在磺胺类药物及生物样品中碱基核苷等亲水性物质的分离分析中有一定应用。     

引言

色谱柱是色谱分离分析的“心脏”,而色谱柱的分离性能主要由色谱固定相的性质所决定;因此,液相色谱技术的发展与色谱固定相的创新密切相关,如近年来细粒度(＜3 [WTBZ]μ[WTB4]m)固定相的研制成功为高压液相色谱(UHPLC)技术的发展奠定了基础。色谱固定相一直以来也是色谱研究领域的前沿和热点。近年来,整体柱材料、超细色谱固定相和基于介孔纳米材料的固定相等制备技术得到了快速发展,其在复杂样品的高效分离分析和样品预处理中的应用也获得了广泛的关注,并取得了重要进展。     

原子转移自由基聚合制备PDMAEMA亲水作用色谱固定相及其性能评价

以甲基丙烯酸二甲氨乙酯为单体,2-溴异丁酰溴为引发剂,CuBr/五甲基二乙烯基三胺(PMDETA)为催化剂,通过原子转移自由基聚合(ATRP)反应,将甲基丙烯酸二甲氨乙酯(DMAEMA)接枝到5μm大孔硅胶表面上,得到了接枝聚合物(PDMAEMA)亲水作用色谱固定相.通过改变反应体系中单体的量,制备了三种不同接枝量的亲水作用色谱固定相,利用元素分析对所制备的固定相进行了表征.详细考察了该固定相的分离性能以及流动相中盐浓度、水含量对溶质保留行为的影响,并将该固定相用于宁心宝胶囊中核苷类化合物的分离和测定.在亲水模式下,该固定相可以基线分离7种核苷类化合物,保留时间随着接枝量的增加而增大,与氨基亲水作用色谱柱相比,该合成柱的分离效率高,溶质在该填料上的保留符合分配作用保留机理.实验结果表明,该填料具有良好的分离性能.     

聚N-异丙基丙烯酰胺硅胶键合固定相的制备与评价

以3-巯丙基三甲氧基硅烷为偶联剂,将聚N-异丙基丙烯酰胺(PNIPAM)键合到硅胶上,制得了键合固定相（SI-PNIPAM）填料,并用元素分析、红外光谱等对其进行了表征。以甲醇-水为二元流动相,用多环芳烃、碱性物质对该固定相进行了色谱评价,并考察了该固定相的适用pH范围及水解稳定性。结果表明:该固定相具有较好的色谱性能与温敏特性,并且在pH 2.5～7.5时稳定性良好。     

聚硅氧烷包夹聚合硅基高效液相色谱固定相的表征及其色谱性能

利用元素分析、红外光谱、扫描电镜及汞压吸附法对制备的聚硅氧烷包夹硅基反相高效液相色谱固定相进行了表征,给出了该固定相的结构信息及其与色谱性能的关系;用滴定法测定了该固定相表面硅羟基数目;考察了该固定相对碱性化合物的分离性能;由表征和色谱性能考察结果可知,该固定相表面的羟基基本被覆盖,因此,可在碱性流动相中长期使用。     

姜黄素键合硅胶固定相的制备、表征及色谱性能

通过γ-［(2,3)-环氧丙氧］丙基三甲氧基硅烷(KH-560)偶联剂将具有抗菌功能的植物有效成分姜黄素键合到硅胶上,制备了姜黄素液相色谱键合硅胶固定相(CCSP)。采用元素分析、红外光谱和热分析对该固定相结构进行了表征。以甲醇和水为二元流动相,不同的中性、酸性和碱性化合物为溶质探针,并用ODS柱作参比,对固定相的色谱性能及保留机理进行了研究。研究结果表明,姜黄素键合固定相不仅具有良好的反相色谱性能,同时由于配体结构中所含有的基团形成了含芳环的共轭体系,从而引入了n-π和π-π作用位点,所含的羟基和β-二羰基与溶质之间存在偶极-偶极和氢键作用,与ODS相比,该固定相在极性化合物分离中占优势,且分析速度较快。     

氨基甲酸酯功能化离子液体高效液相色谱固定相的制备与初步评价

合成一种了氨基酸衍生物：4,4′-二苯亚甲基桥联-二[2-(1-咪唑基)-3-苯基丙醇氨基甲酸酯](ImPh-Carb),并将其键合到硅胶上制备了一种新的氨基甲酸酯功能化的离子液体HPLC固定相（ImPh-Carb-Silica）。 利用1H NMR、13C NMR、MS和FTIR对ImPh-Carb进行了表征;通过FTIR和元素分析对ImPh-Carb-Silica固定相进行了表征,根据N含量计算得到ImPh-Carb-Silica的键合量为0.19 mmol/g。 以5种芳烃、5种酚类化合物和4种有机磷农药为分析物,分别在正相和反相色谱模式下对固定相的色谱分离性能进行了评价,同时考察了流动相的变化与溶质保留因子lg k之间的关系。 结果表明,该固定相与溶质分子间存在多重作用力,如疏水、氢键、π-π和偶极-诱导偶极作用等,使其能同时在正相和反相色谱模式下使用;在正相色谱条件下固定相对酚类化合物和有机磷农药表现出较好的分离选择性。     

大黄素键合硅胶固定相的制备及其在核苷碱基药物分离中的研究

通过γ-[(2,3)-环氧丙氧]丙基三甲氧基硅烷(KH-560)偶联剂将具有抗菌功能的植物有效成分大黄素键合到硅胶上,制备了大黄素液相色谱键合固定相(EDSP)。采用元素分析、红外光谱和热分析对该固定相的结构进行表征。以嘧啶、嘌呤和核苷为溶质探针,并用ODS柱做参比,对固定相的色谱性能及保留机理进行了研究。研究结果表明,该固定相具有类似ODS的反相色谱性能,除疏水作用外,由于大黄素的大π共轭体系,为溶质提供了n-π和π-π作用位点;且两个邻位羟基和两个羰基的存在,能够与溶质之间发生氢键作用和偶极-偶极作用。与ODS柱相比,该固定相在极性化合物分离中占优势,且分析速度较快。此外,实验还发现,该固定相能较好地分离二甲苯同分异构体,预示着该固定相有一定的立体选择性分离能力。     

用于碱性物质分离的酰胺型反相色谱键合相的制备及评价

 采用先对硅胶进行氨丙基化 ,然后与辛酰氯键合的方法 ,在国内首次制备了“内嵌”极性官能团酰胺键的反相色谱填料。以甲醇 水为二元流动相 ,用含有中性、酸性和碱性有机化合物的混合物评价了该固定相的疏水性、选择性和亲硅醇基效应 ,并考察了该填料适用的 pH值范围及水解稳定性。结果表明 ,该固定相具有较好的色谱性能 ,且在 pH 2 5～ 7 5时稳定性能良好 ,可有效地用于碱性化合物的分离分析。     

酰胺型键合相的简便制备及评价

 提供了一种酰胺型键合相的简便合成方法 ,即氨丙基三乙氧基硅烷先与烷基酰氯反应 ,然后再键合到硅胶上。该合成路径具有很好的重复性 ,得到的最后产物的硅胶表面键合链均一。用元素分析、核磁共振和红外光谱对最后产物进行了表征。以甲醇和水为二元流动相 ,用包括碱性、酸性和中性有机化合物在内的混合物对该键合相进行了评价 ,并考察了该键合相的适用pH范围及水解稳定性。结果表明 ,该键合相具有较好的性能 ,且在 pH 2 5～ 7 5时稳定性能良好 ,可有效地用于碱性化合物的分析分离。     

A novel silica-based column packing for reversed-phase HPLC of basic compounds

Summary A novel bonded phase for reversed-phase HPLC was synthesized in two steps. Octylamine was first reacted with β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (β-ECTS) and then the intermediate product was coupled onto porous silica. The prepared packing was characterized by elemental analysis, solid-state¹³C NMR and Fourier transform infrared (FT-IR). Chromatographic evaluations were carried out by using a mixture of organic compounds including acidic, basic and neutral analytes and methanol-water as binary mobile phase. The results showed that the stationary phase has excellent chromatographic properties and is resistant to hydrolysis between pH=2≈8. It can be used efficiently for the separation of basic compounds.     

大黄酸键合硅胶固定相的简便制备及色谱性能评价

以大黄酸为原料,γ-氨丙基三乙氧基硅烷(KH-550)为偶联剂,简便制备了一种新型羧基键合硅胶固定相(RBSP),并用红外光谱、热重分析及元素分析对其结构进行表征.考察了流动相中甲醇含量对键合固定相色谱性能的影响,并以含酸性、中性和碱性化合物的混合物为溶质,评价了RBSP的色谱性能.以甲醇-水为流动相,用C18柱作参比,研究了该键合硅胶作为HPLC固定相对两种大豆异黄酮化合物和几种生物碱基的分离,并对其色谱分离机理进行了初步探讨.实验结果表明,该固定相(RBSP)具有较好的反相色谱性能,同时由于键合相中含有酚羟基及酰胺基团,能为多种溶质提供作用位点,对极性化合物的分离具有明显优势,且分离速度快,可有效用于极性化合物的分离分析.     

新型大孔硅质酰胺型聚合物键合相的制备及其对蛋白质的分离

大孔硅胶与乙烯基硅烷反应后,再与甲基丙烯酰胺和二乙烯基苯共聚成一种新型分离蛋白质的色谱柱填料。考察了这种色谱填料对蛋白质的分离能力,认为其具有柱效高、惰性好和分离效率高的优点,聚合物键合相的制备重复性好。并探讨了流动相中离子强度和ｐＨ值对蛋白质分离的影响。     

新型高效液相色谱酰胺键合固定相的制备与评价

将YWG-80硅胶和3-氨基丙基三甲氧基硅烷反应后与2-壬基丁二酰氯反应制得一种新型双齿酰胺键合固定相(BABSP-2)。采用元素分析和傅里叶变换红外光谱表征了键合相;用芳香族化合物溶质和甲醇-水二元流动相,考察了键合相的疏水选择性和亲硅醇基活性;评估了在酸性条件下(pH2.5)的水解稳定性。结果表明：BABSP-2能有效抑制残留硅醇基活性,并具有可比的疏水选择性和较好的水解稳定性。     

Preparation and characterization of a new HPLC C18 reversed phase containing thiocarbamate groups

A HPLC stationary phase that possesses an internal thiocarbamate functional group is described. The new C18-thiocarbamate silane was synthesized by the reaction of a trifunctional alkoxysilane with a mercaptan. The silylant agent was bonded to silica (5 μm) and the new stationary phase was then endcapped. Surface characteristics of the packing before and after chemical modification with HMDS and TMCS were determined by different physico-chemical methods, such as elemental analysis and infrared and solid-state ¹³C and ²⁹Si nuclear magnetic resonance spectroscopies. Chromatographic properties of the C18-thiocarbamate silica were evaluated under reversed phase conditions by separation of four different test mixtures that including compounds from the Engelhardt, Tanaka, and Neue test mixtures. Chromatographic evaluations of the C18-thiocarbamate phase show promising results for the separation of basic analytes.     

Synthesis of porphyrinoids with silane anchors and their covalent self-assembling and metallation on solid surface

We have synthesized a set of porphyrin and phthalocyanine compounds with two different silane anchors. Syntheses of the anchor-substituted chromophores have been carried out via hydrosilylation of alkene derivatives, catalyzed by platinum complexes. The reduction side-process was suppressed using specific anchor/catalyst pairs, and the silane-containing compounds were successfully isolated from hydrogenated by-products in pure form with good yields. The target porphyrinoids having stable reactive silane anchors possess the ability to self-assemble on metal oxides and quartz surfaces and optical fibers. Covalent attachment is done in one-step, which makes the bonding process fast and easy. Immobilized chromophores were further converted by on-surface reactions into Zn(II) and Mg(II) metal complexes. The metallation time was found to be as fast as 1 min for Zn ion. Bonding densities calculated from the absorbances of the deposited layers give rough estimations for packing of the molecules on various substrates and evidence for monomolecular layers formation.     

A simple preparation of stationary phase of alkylamide reversed-phase liquid chromatograph for the separation of basic substances.

A simple preparation process of alkylamide phase for reversed-phase HPLC (RP-HPLC) is described. The process includes aminopropyltrimethoxysilane firstly reacted with octanoyl chloride, then the intermediate was coupled onto porous silica. The resultant bonded silica has a reproducible ligand surface concentration and homogenous bonded ligand distribution on the porous silica. Characterization of prepared packing was carried out with elemental analysis, solid-state 13C NMR and Fourier transform infrared (FT-IR). Chromatographic evaluations were carried out by using a mixture of organic compounds including acidic, basic and neutral analytes under methanol/water as binary mobile phase. The results showed that the stationary phase have excellent chromatographic properties and can be efficiently used for the separation of basic compounds.     

八碳烯和十八碳烯与二乙烯基苯交联聚合包覆二氧化钛固定相的合成及反相色谱性能的评价

分别合成了八碳烯-1以及十八碳烯-1与二乙烯基苯交联聚合包覆二氧化钛固定相,对它们进行了元素分析和漫反射红外光潜的表征,并用这两种填料分离了稠环芳烃、烷基苯、苯胺类碱性化合物、卤代苯.实验证明这种交联聚合包覆崮定相对有机流动相和碱具有高稳定性.最后将两种固定相用于合成药中辛伐他汀和洛伐他汀的分离检测.     

Preparation and Evaluation of 3,5-Dinitrobenzoyl-Bonded Silica Gel Stationary Phase for HPLC

Column packing materials are always a key factor influencing the development of high-performance liquid chromatography (HPLC). In this paper, a new preparation method of 3,5-dinitrobenzoyl-bonded silica gel stationary phase (DNB) for HPLC was developed by using N-(β-aminoethyl)-γ-aminopropyl-methyldimethoxy silane as coupling reagent. Its structure was characterized by elemental analysis, diffuse reflectance infrared Fourier transform spectroscopy, and thermal analysis. The surface concentration of 3,5-dinitrobenzoyl ligand is 2.082 μmol m⁻², according to the carbon content of elemental analysis. The chromatographic performance of new packing was evaluated by using different solute probes, such as alkylbenzenes, polycyclic hydrocarbons (PAHs), phenols, naphthalene derivatives, nitrophenol positional isomers, and sulfonamides. The results show that DNB was of the reversed-phase packing kind with weak hydrophobicity and versatile chromatographic property compared with octadecyl silane. The charge transfer between the dinitrobenzoyl ligand and the analytes plays a significant role in the separation of phenols and naphthalene derivatives. In addition, electrostatic, hydrogen-bonding, and dipole-dipole interactions are responsible for the above separations, which improve the selectivity of DNB for solutes. An advantage of DNB is that it is suitable for the separation of the basic compounds containing nitrogen atoms without a capped process because the spacer containing nitrogen atoms can shield the residual silanols from DNB. Translated from Chinese Journal of Chromatography, 2005, 23(3) (in Chinese)