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。     

新型吡咯烷键合反相高效液相色谱固定相的制备与研究（英文）

正A new ionic liquid-based high-performance liquid chromatography stationary phase is reported.A derivative of N-methyl pyrrolidinium tetrafluoroborate was covalently immobilized on the surface of silica particles to prepare silica-based N-methyl pyrrolidinium tetrafluoroborate(SilprMP BF4)stationary phase.The obtained ionic liquid-modified silica was evaluated and confirmed by elemental analysis,infrared spectroscopy,and thermogravimetric analysis.A column was packed with the modified particles.The retention behavior of aromatic compounds,alkyl benzenes,and acidic and basic compounds on the SilprMP BF4 stationary phase was studied under reversed-phase liquid chromatography conditions.The effect of the eluent pH on the separation of the acidic and basic compounds was also studied.The new stationary phase involves multiple retention mechanisms,such as electrostatic,hydrophobic,ion-dipole,and anion-exchange interactions,which might lead to multipurpose separation media.     

Cholesteric bonded stationary phases for high-performance liquid chromatography: a comparative study of the chromatographic behavior

The properties of four cholesteric bonded stationary phases differing in the nature of the spacer and the end-capping were assessed using simple chromatographic tests based on the retention of nonpolar compounds and of planar or nonplanar probe solutes. All cholesteric columns showed a hydrophobicity close to that of conventional octadecyldimethylsilyl (ODS) materials. Non-end-capped cholesteric bonded phases showed greater selectivity than ODS ones and both end-capped cholesteric bonded phases exhibit behavior intermediate between that of the non-end-capped original material and that of the ODS bonded phase.     

Synthesis of a propyldimethylphenylsilane stationary phase using the allyl bonded phase as an intermediate

Summary A propyldimethylphenylsilane stationary phase was prepared by a hydrosilylation reaction on the double bond of an allyl bonded phase intermediate. The carbon load on the silica was between 8.8–9.0%. Evaluation of the material by FTIR indicated high conversion of the double bond by the hydrosilylation reaction. The bonded material displayed reversedphase properties as determined by the retention behavior of alkylarylketones but it was less hydrophobic than either C-8 or C-18. The stability at both low and high pH was excellent. Separations of pharmaceutical compounds, a mixture of anilines, and a mixture of dopamine and epinephrine were satisfactory.     

High-performance liquid chromatography of metal ions on a bonded stationary phase

Summary High performance liquid chromatography was used to separate Cu²⁺, Ni²⁺, and Zn²⁺ ions. A column packed with a -diketone bonded phase on silica gel and a mobile phase composed of trifluoroacetylacetone in acetone was used for the separation. After post-column reaction with a color-forming reagent, the metals were detected by absorption in the visible region.Currently assigned to 1155th Technical Operations Squadron, McClellan Air Force Base, California, 95652, USA     

Chromatographic characterization of a bonded liquid crystal stationary phase for HPLC

Summary A chromatographic and thermodynamic study of the compound [4-(allyloxy)benzoyl]-4-methoxyphenyl (ABMP) as a model of a chemically bonded liquid crystal stationary phase for HPLC was undertaken. A number of polycyclic aromatic hydrocarbons (PAHs) and two small solutes, carvone and pulegone, were studied under varying solvent and temperature conditions. Plots of log k vs. % organic in the mobile phase were not completely linear in all cases. The van't Hoff plots revealed at least one phase transition. The enthalpies of solute transfer from the mobile phase to the ABMP phase were determined for several PAHs. All tests indicate that ABMP possess liquid crystal properties when bonded to particulate silica.     

改性松香键合二氧化硅高效液相色谱固定相的制备及其对三七总皂苷的分离

三七中发挥药效的主要成分为三七皂苷R1、人参皂苷Rg1、人参皂苷Re、人参皂苷Rb1和人参皂苷Rd,用于贫血、冠心病、高血压、脑卒中后遗症等疾病的治疗,但其化学成分多且难分离.将氢化松香丙烯酸羟乙酯(HRHA)通过巯基-烯点击化学反应键合到烷基化硅胶表面,制备出一种新型的改性松香键合二氧化硅高效液相色谱固定相(SiO2...     

Evaluation of ionic liquid stationary phases for one dimensional gas chromatography-mass spectrometry and comprehensive two dimensional gas chromatographic analyses of fatty acids in marine biota

Ionic liquid stationary phases were tested for one dimensional gas chromatography-mass spectrometry (GC-MS) and comprehensive two dimensional gas chromatography (GC×GC) of fatty acid methyl esters from algae. In comparison with polyethylene glycol and cyanopropyl substituted polar stationary phases, ionic liquid stationary phases SLB-IL 82 and SLB-IL 100 showed comparable resolution, but lower column bleeding with MS detection, resulting in better sensitivity. The selectivity and polarity of the ionic liquid phases are similar to a highly polar biscyanopropyl-silicone phase (e.g. HP-88). In GC×GC, using an apolar polydimethyl siloxane×polar ionic liquid column combination, an excellent group-type separation of fatty acids with different carbon numbers and number of unsaturations was obtained, providing information that is complementary to GC-MS identification.     

Characterization of the polyphenolic fraction of pomegranate samples by comprehensive two-dimensional liquid chromatography coupled to mass spectrometry detection

Abstract

Punica granatum L., commonly known as pomegranate, is an ancient fruit widely consumed all over the world as fresh fruit or juice. In addition, it is extensively used in therapeutic formulas, cosmetics and food seasonings. The fruit is native to Afghanistan, Iran, China and the Indian sub-continent. The pomegranate market has steadily grown, presumably due to the increasing demand of health-conscious consumers for products with potential beneficial effects on human health, due to the synergistic presence of a unique and complex phytochemical composition that enclose anthocyanins, phenolic acids and hydrolysable tannins. Conventionally, for their analysis liquid chromatography is employed even though it can present some drawbacks in terms of resolving power. In this contribution, as a valuable alternative, comprehensive two-dimensional liquid chromatography with “shifted gradients” in the second dimension, was applied for the characterization of three pomegranate samples, leading to the identification of 37 different polyphenolic compounds.     

Synthesis and characterization of a new type of chemically bonded liquid crystal stationary phase for HPLC

Summary Two commercially available liquid crystals, 4-cyano-4′-n-pentyl-1,1′-bipheny and 4-cyano-4′-n-pentoxy-1,1′-bipheny, are bonded to a silica hydride surface via hydrosilation in the presence of a free radical iniator, t-butyl peroxide. Elemental analysis, diffuse reflectance Fourier trans-form infrared spectroscopy, and¹³C and²⁹Si CP-MAS NMR spectroscopy are used to confirm the success of the bonding reaction. The¹³C CP-MAS spectra suggest a difference in the bonded phase morphology of the two materials. Static hydrolytic stability tests indicate these materials do not degrade significantly in both acidic and basic solutions. Chromatographic tests confirm that these two bonded phase behave differently with respect to their retention of PAHs, alkyl-substituted benzenes and benzodiazepines.     

基于高效液相色谱定量指纹图谱和液相色谱-质谱联用定量的酸枣仁提取物质量考察

酸枣仁具有显著的改善睡眠和抗焦虑等作用,其提取物在助眠类功能食品开发中应用前景广阔。但目前市场上酸枣仁提取物质量参差不齐,缺乏统一标准,企业在使用时面临较大的质量风险,因此亟须建立一种准确、全面的内控质量评价方法。针对酸枣仁提取物中黄酮和皂苷两类主要活性成分紫外响应差异巨大且水提物中皂苷成分含量低的问题,该研究建立了酸枣仁水提物HPLC定量指纹图谱方法,共标定了8个共有峰。通过对照品指认、文献比对以及高效液相色谱-四极杆飞行时间质谱数据解析,8个共有峰均为黄酮类化合物,该方法可同时实现7种黄酮成分的半定量对比分析和斯皮诺素的含量测定;采用超高效液相色谱-三重四极杆质谱,在正离子模式下,以多反应监测扫描方式可实现酸枣仁皂苷A和B的含量测定;最终以雷达图展现上述10种成分的半定量和定量数据。应用上述方法,该研究对比分析了实验室自制的3批酸枣仁水提物和15家供应商的15批提取物样品。结果显示,实验室自制的3批酸枣仁水提物虽然原料来自不同饮片企业,但总体差异性不大,而不同厂家提供的酸枣仁提取物样品成分含量差异巨大,提示不同厂家存在辅料稀释、理枣仁掺假和醇提或纯化富集等情况。该法为企业制定内控质量标准和筛选合格供应商提供了依据。     

基于手性固定相的超高效液相色谱-串联质谱法检测小麦及其加工制品中的腈菌唑对映体

建立了手性超高效液相色谱-串联质谱检测小麦及其加工制品中腈菌唑对映体残留的分析方法.样品经乙腈提取,N-丙基乙二胺(PSA)和C18净化,手性色谱柱Lux Cellulose-1(150 mm×2.0 mm,3μm)分离,质谱电喷雾正离子扫描(ESI+),多反应监测(MRM)模式进行检测.为准确定量,考察了小麦籽粒及其...     

姜黄素键合硅胶固定相HPLC分离水溶性维生素和核苷

以ODS为参比,研究了5种水溶性维生素和5种核苷在姜黄素键合硅胶固定相(CCSP)上的色谱行为,考察了甲醇、流动相pH和离子强度对CCSP分离这类极性化合物的影响,探讨了该新固定相的色谱保留机理。结果表明,在V(甲醇)∶V(0.01 mol/L NaH2PO4)=40∶60(pH 3.5)流动相体系中,5种水溶性维生素在CCSP上实现较好分离;核苷的分离则是在以纯水为流动相的条件下实现的。与ODS柱相比,在相同条件下,CCSP对5种水溶性维生素具有较高的选择性,洗脱顺序与ODS具有显著差异,且保留明显比ODS强(B6除外);与此相反,相同色谱条件下,CCSP对核苷的保留比ODS弱,CCSP可实现核苷的简便有效分离,同时胸苷与黄苷的洗脱顺序也与ODS不同。以上说明不同保留机理的存在,CCSP具有典型的反相色谱特征,但疏水性比ODS弱;极性的配体使CCSP在对溶质的分离分析中除疏水作用外,还存在n-π和π-π作用、氢键作用、偶极-偶极等作用;协同作用的结果使CCSP在水溶性极性化合物的分离分析中显示出优势。     

Imatinib metabolite profiling in parallel to imatinib quantification in plasma of treated patients using liquid chromatography-mass spectrometry

Besides affecting the systemic bioavailability of the parent drug, drug metabolizing enzymes (DMEs) may produce bioactive and/or toxic metabolites of clinical interest. We have investigated the capability to analyze simultaneously the parent drug and newly identified metabolites in patients' plasma by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The anticancer drug, imatinib, was chosen as a model drug because it has opened a new area in cancer therapy and is given orally and chronically. In addition, resistance and rare but sometimes severe side effects have been reported with this therapy. The quantification of imatinib and the profiling of its metabolites in plasma were established following three steps: (1) set-up of a generic sample extraction and LC-MS/MS conditions, (2) metabolite identification by LC-MS/MS using either in vitro incubations performed with human liver microsomes (HLMs) or patient plasma samples, (3) the simultaneous determination of plasma levels of imatinib and 14 metabolites in the plasma samples of 38 patients. Partial or cross method validation has been done and revealed that precise determinations of metabolite levels can be performed whereas pure standards are not available. Preliminary results indicate that the disposition of imatinib and its metabolites is related to interindividual variables and that outlier metabolite profiles can be revealed. This article underscores that, in addition to usual therapeutic drug monitoring (TDM), LC-MS/MS methods can simultaneously record a complete drug metabolic profile enabling various correlation studies of clinical interest.     

Liquid Chromatography with mass spectrometry analysis of mycotoxins in food samples using silica hydride based stationary phases

Liquid chromatography with mass spectrometry analysis of selected food samples using silica hydride stationary phases allowed for the identification and quantification of common mycotoxins including aflatoxin B1, B2, G1, G2, ochratoxin A, and fumosinin B1. Phenyl and C₁₈ columns showed relatively similar selectivity based on hydrophobicity but the phenyl phase provides an additional mechanism, π–π interaction. The most hydrophobic of the analyzed compounds was more strongly retained on the C₁₈ column and also has fewer unsaturated sites, which limited the interaction with the phenyl phase. Bean, maize, rice, and wheat samples were harvested and stored under conditions conducive to fungal development, and all samples presented toxin contamination exceeding the maximum tolerable limits.     

Retention properties of acetone-water mobile phases on a biphenylsiloxane-bonded silica stationary phase in reversed-phase liquid chromatography

The solvation parameter model system constants and retention factors were used to interpret retention properties of 39 calibration compounds on a biphenylsiloxane-bonded stationary phase (Kinetex biphenyl) for acetone-water binary mobile phase systems containing 30–70% v/v. Variation in system constants, phase ratios, and retention factors of acetone-water binary mobile phases systems were compared with more commonly used acetonitrile and methanol mobile phase systems. Retention properties of acetone mobile phases on a Kinetex biphenyl column were more similar to that of acetonitrile than methanol mobile phases except with respect to selectivity equivalency. Importantly, selectivity differences arising between acetone and acetonitrile systems (the lower hydrogen-bond basicity of acetone-water mobile phases and differences in hydrogen-bond acidity, cavity formation and dispersion interactions) could be exploited in reversed-phase liquid chromatography method development on a Kinetex biphenyl stationary phase.     

氟环唑外消旋体在纤维素-三(3,5-二甲基苯基氨基甲酸酯)手性固定相上的高效液相色谱法拆分

在纤维素-三(3,5-二甲基苯基氨基甲酸酯)（CDMPC）手性固定相上,分别采用正相、反相及极性有机相色谱模式对氟环唑外消旋体进行了拆分,并考察了流动相组成在手性识别中对手性分离的影响。氟环唑在Chiralcel OD-H手性色谱柱（填充CDMPC手性固定相）上采用反相色谱模式,以甲醇-水(体积比为80∶20)为流动相,获得了最佳的拆分,其两对对映异构体的分离度Rs分别为1.64和6.50。     

丁香酚键合硅胶液相色谱固定相的制备和色谱性能

采用固液相表面连续反应法,先将偶联剂γ-[(2,3)-环氧丙氧]丙基三甲氧基硅烷(KH-560)键合到球形硅胶表面,然后再将植物有效成分丁香酚与硅胶上的KH-560活性基团反应,合成了丁香酚键合硅胶液相色谱固定相(EGSP)。采用元素分析、热重分析和红外光谱对该固定相的结构进行了表征。以萘作为溶质探针,乙腈-水(35:65, v/v)为流动相,流速为0.8 mL/min,测得EGSP柱的柱效。以一系列的中性、碱性和酸性化合物为溶质探针,C₁₈柱和苯基柱作参比,对该固定相的色谱性能及保留机理进行了研究。结果表明,硅胶表面成功键合上了丁香酚配体,键合量为0.28 mmol/g, EGSP柱理论塔板数约为24707 N/m。该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含有芳环、烯基和甲氧基,还能与溶质发生π-π电荷转移、偶极-偶极和氢键作用。与传统的反相C₁₈柱和苯基柱相比,EGSP在极性芳香族化合物的快速、简便分离中占优势。     

基于柱前衍生-超高效液相色谱-质谱联用技术的植物提取液中氨基化合物代谢谱分析

氨基化合物在植物生长发育中起着重要作用。本文建立了一种基于柱前衍生-超高效液相色谱-质谱联用技术的植物提取液中氨基化合物代谢谱的分析方法。以烟草鲜叶为例,共检测出87种氨基化合物。其中43种氨基化合物的定量分析结果表明,方法的线性相关系数在0.993~0.999之间,线性范围可达到4个数量级,检出限为0.03~6.58 ng/mL,日内、日间精密度分别为0.7%~15.6%、0.8%~22.9%,回收率为74.4%~122.7%。采用该方法考察了打顶对不同部位烟草鲜叶中氨基化合物代谢谱的影响,结果显示打顶处理对上部叶影响最大,打顶后上部叶氮代谢主要流向生物碱合成方向。该方法充分利用了三重四极杆串联质谱和高分辨串联质谱技术的优势,可实现植物提取液中氨基代谢物的高选择性、高灵敏度分析。