Novel guanidinium-based ionic liquids as stationary phases for capillary gas chromatography

The present study describes guanidinium-based ionic liquids（GBILs） as stationary phases for capillary gas chromatography （CGC） and to the best of our knowledge,no related reports are available up to now.In this study,a hexaalkylguanidinium ionic liquid（DOTMG-NTf;） was synthesized and coated statically onto capillary columns.Selectivity of the stationary phase was evaluated by separating Grob test mixture,test mixture,alcohols mixture,and fatty acid methyl esters mixture,and thermal stability was investigated as well.The present study demonstrates that GBILs as CGC stationary phases exhibit satisfactory selectivity and thermal stability and have a great potential as new candidates for CGC stationary phases.

Optimization strategies for separation of sulfadiazines using Box-Behnken design by liquid chromatography and capillary electrophoresis

Development of effective chromatographic or electrophoretic separation involves judicious deciding of selection of optimal experimental conditions that can provide an adequate resolution at a reasonable run time for the separation of interested components. Box-Behnken factorial design was effectively applied for the separation optimization of eight structurally related sulfonamides using capillary zone electrophorosis and reverse high performance liquid chromatography. Optimum values for volume ratio of THF to H2O in eluent, column temperature and flow rate of eluent are found as 12 to 88, 35℃ and 1.0 mL/min, respectively. Box-Behnken modified optimization model is extended to separation by capillary electrophoresis (CE). While using CE, a satisfactory separation is achieved with a minimum resolution larger than 1.0 for a separation time less than 10 min.

Retention behaviors of novel ionic liquid stationary phases and their selectivity for capillary gas chromatography

One chloride-terminated ionic liquid（CTIL） and two hydroxyl-terminated ionic liquids（HTILs） were synthesized and used as stationary phases for capillary gas chromatography（CGC）.Molecular interactions of these stationary phases were evaluated by Abraham solvation parameter model,indicating that the CTIL exhibits remarkably strong H-bond basicity and the HTILs possess both H-bond basicity and acidity.The molecular interactions were further confirmed by separation of a complex mixture consisting of ketones,aldehydes,esters,alcohols and aromatic compounds.It was found that the obtained solvation parameters correlate well with the chromatographic performances of the analytes in terms of elution order and resolution.The well correlated relationship between the solvation parameters and the selectivity of the CTIL and HTILs stationary phases is quite helpful in predicting and understanding the retention behaviors of different types of analytes on these stationary phases.

Selectivity of guanidinium ionic liquid for capillary gas chromatography

A guanidinium ionic liquid,N,N,N＇,N＇-tetrahexyl-N＂,N＂-dimethylguanidinium bis（trifluoromethane）sulfonylimide（THDMGNTf2）, was synthesized and used as stationary phase for capillary gas chromatography.In comparison with imidazolium ionic liquid stationary phase,the present new stationary phase exhibits quite different selectivity and behaves more like a low polar stationary phase.The guanidinium ionic liquid of THDMG-NTf2 exhibited better separation of Grab test mixture than imidazolium ionic liquid of 1-octyl-3-butylimidazolium bis（trifluoromethane）sulfonylimide（OBIM-NTf2）.Solvation parameter model was also used to evaluate the selectivity of THDMG-NTf2.Additionally,essential oil of Magnolia biondii Pamp was analyzed to further evaluate the selectivity of THDMG-NTf2 for a sample of complicated components.Satisfactory separation of the essential oil was achieved on a THDMG-NTf2 column（10 m） while using a commercial column（30 m） as reference.The present study shows that the guanidinium ionic liquid possesses novel chromatographic selectivity and has great potential for wide applications.

Advances in Capillary Chromatography

Capillary columns are used in both capillary liquid chromatography and capillary electrochromatography. The design for capillary liquid chromatography is discussed in comparison with capillary gas chromatography. The difference of diffusion coefficient in gas and liquid phase is a key role. The study for obtaining a high performance capillary liquid chromatography is discussed. Capillary electrochromatography is recently interesting for its instinct ability to realize a high performance chromatography. Capillary electrochromatography with and without pressurized flow is reviewed briefly. Instrumentation for capillary electrochromatography with pressurized flow is discussed. The port of splitting, and gradient elution of both solution and potential are described. The new findings of both the variation of column resistance and capacity factor according to the value of applied electric voltage are also discussed.

寡核苷酸药物生物分析方法的研究进展

寡核苷酸药物是具有不同功能化学修饰的DNA或RNA,主要在基因水平上发挥治疗的作用。到目前为止,已经批准16种寡核苷酸药物用于临床治疗,这也导致了人们对寡核苷酸药物生物分析的兴趣日益增加。尤其需要强大的生物分析工具来研究这些药物的质量控制及体内的药代动力学研究。该篇综述总结了液相色谱、毛细管凝胶电泳、杂交酶联免疫吸附技术在检测寡核苷酸药物的优缺点,为该类药物的研究及质量控制提供一定的思路。

用于检测羧酸的基于高效毛细管电泳的微流控芯片

设计了一种可以进行高效毛细管电泳分析的微流控芯片,微流控芯片具有一个十字架结构的沟道,沟道横截面的尺寸为100μm×50μm。利用5-氨基甲基荧光素作为荧光探针,使用乙腈溶液与磷酸盐缓冲液作为流动相进行高效液相色谱分析,等量洗脱确认了丙酸到十八烷酸(C3~C18)的衍生物色谱图,并通过高效毛细管电泳分析将丙酸(C3)、己酸(C6)、癸酸(C10)进行分离,成功分离C3和C10,C3和C10的分离度为2.2,分离效果良好。此外,针对高效毛细管电泳分析出现的不稳定电渗现象而导致实验数据不稳定的情况,加入阳离子聚合物六甲溴铵和阴离子聚合物硫酸葡聚糖钠盐形成连续的多个离子聚合物涂层,使得微流控芯片对羧酸检测的稳定性大大提高。

Multiple Chromatographic and Chemometric Methods for Quality Standardization of Chinese Herbal Medicines

Quality standardization of complementary medicine is fundamental for industry and practice as it underpins the quality,safety and efficacy of Chinese herbal medicines.Current herbal standardizations are often based on the quantitative analysis of a single compound,which may not reflect the total characteristic,bioactive and toxic nature of the herbs or products.Therefore,there is a need to establish an internationally recognized methodology for quality standardization of Chinese herbal medicines.The analytical methods reviewed in this article are pharmacognosy,TLC,HPLC,LCMS,CE and chemo-metrics.This article also covers the developments and applications of these methods in quality standardization.Recent advances show that a combination of these methods creates an overall chemical profile of each herb.This is supported by results reviewed in this article and obtained in our laboratory tests on medicinal herbs including Hypericum perforatum,Morinda officinalis and Centella asiatica.Significant variations in active components have been observed between herbal samples and products.It is proposed that the identification of active components,pharmacological activities and eventual clinical applications are required for a comprehensive quality standardization system.Our findings indicate that the combination of various chromatographic and chemometric methods will advance the methodology of quality standardization and enhance the overall confidence in herbal medicine for the health practitioner and the public.

基于碳点的色谱分离材料研究进展

色谱分离的核心是色谱柱,色谱柱的灵魂是色谱分离材料,色谱分离材料的种类和性质直接决定色谱的分离模式和分离性能。碳点作为一类新型的零维碳纳米材料,自2004年被首次报道以来,凭借其广泛的原料来源、低毒性、易于功能化、优异的生物相容性和抗光漂白性等独特性能,已广泛应用于生物成像、发光二极管、传感、催化等领域,并呈现出蓬勃的生机。同时,碳点还具有设计性强、粒径大小适中等优势,将其引入色谱分离新材料中开发高选择性的色谱固定相具有重要意义。本文首先简要回顾了碳点的分类、合成策略、发展历程,然后聚焦于色谱分离材料领域,系统综述了近年来碳点在液相色谱固定相(含亲水色谱、反相色谱、混合色谱、手性色谱等)、气相色谱固定相和毛细管电色谱固定相方面的最新研究进展,特别强调了各类固定相的制备方法及其应用,并对碳点在色谱分离材料领域的发展前景和未来努力方向进行了分析和展望,期望为基于碳点的色谱分离新材料的理性设计及应用提供一些参考。

顶空进样毛细柱气相色谱法检测水中三氯甲烷研究

采用顶空气相色谱法检测水中三氯甲烷的质量浓度,毛细管色谱柱为HP-5,检测器为电子捕获检测器(ECD)。实验结果表明:三氯甲烷的线性范围为0~60.0μg/L,相关因子为0.9995;精密度为2.8%~4.3%;加标回收率91.8%~104.0%;检出限为0.2μg/L。该方法简便、快速,具有较好的精密度与准确度,可用于水中三氯甲烷的测定。

可去除染料--N-聚糖多方法深入分析中的缺失环节

As the roles of glycans in health and disease continue to be unraveled,it is becoming apparent that glycans’immense complexity cannot be ignored.To fully delineate glycan structures,we developed an integrative approach combining a set of cost-effective,widespread,and easy-to-handle analytical methods.The key feature of our workflow is the exploitation of a removable fluorescent label—exemplified by 9-fluorenylmethyl chloroformate(Fmoc)—to bridge the gap between diverse glycoanalytical methods,especially multiplexed capillary gel electrophoresis with laser-induced fluorescence detection(xCGELIF)and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOFMS).Through the detailed structural analysis of selected,dauntingly complex N-glycans from chicken ovalbumin,horse serum,and bovine transferrin,we illustrate the capabilities of the presented strategy.Moreover,this approach“visualizes”N-glycans that have been difficult to identify thus far—such as the sulfated glycans on human immunoglobulin A—including minute changes in glycan structures,potentially providing useful new targets for biomarker discovery.

茵陈蒿中芹菜素6,8-二-C-β-D-葡萄糖苷的确认及含量测定

目的 确认我国内地产茵陈蒿中存在芹菜素6,8-二-C-β-D-葡萄糖苷,并建立测定其含量的高效液相色谱(HPLC)法。方法 采用高效液相色谱-二极管阵列检测器(HPLC-DAD)法鉴定,色谱柱为Symmetry C18柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.1%磷酸水溶液(梯度洗脱),流速为1.0 mL/min,柱温为30℃,检测波长为200~400 nm;采用超快液相色谱-三重四极杆飞行时间串联质谱(UFLC-Triple-Q-TOF-MS/MS)法鉴别,电喷雾电离负离子模式下采集数据,PeakView 1.6软件提取总离子流图;采用对照品比对,比较对照品溶液和供试品溶液色谱图中色谱峰的保留时间、紫外吸收光谱及总离子流图中相同保留时间分子离子峰的一级和二级质谱数据,鉴定茵陈蒿中的芹菜素6,8-二-C-β-D-葡萄糖苷;同时,采用HPLC法,于270 nm波长处测定35批茵陈蒿样品中芹菜素6,8-二-C-β-D-葡萄糖苷的含量。结果 对照品溶液和供试品溶液色谱图中相同保留时间色谱峰的紫外吸收光谱基本相同,总离子流图中相同保留时间分子离子峰的一级和二级质谱数据基本一致。芹菜素6,8-二-C-β-D-葡萄糖苷质量浓度在0.082 3~16.640μg/mL范围内与峰面积线性关系良好(r=0.999 9,n=8);定量限和检测限分别为36.67 ng/mL和20 ng/mL;日内精密度、日间精密度、稳定性和重复性试验的RSD均小于4.10%(n=6);平均加样回收率为96.37%,RSD为1.40%(n=6)。35批茵陈蒿样品中芹菜素6,8-二-C-β-D-葡萄糖苷含量在0.037~0.339 mg/g之间,其中产地为河南的平均含量最高(0.144 mg/g)。结论 确认了我国内地产茵陈蒿中存在黄酮二糖碳苷类成分芹菜素6,8-二-C-β-D-葡萄糖苷。所建立方法操作简单、重复性好,可用于茵陈蒿中芹菜素6,8-二-C-β-D-葡萄糖苷的含量测定。

On-line trapping/capillary hydrophilic-interaction liquid chromatography/mass spectrometry for sensitive determination of RNA modifications from human blood

RNA modification has recently been proposed to play important roles in biological regulation. The detection and quantification of RNA modifications generally are challenging tasks since most of the modifications exist in low abundance in vivo. Here we developed an on-line trapping/capillary hydrophilic-interaction liquid chromatography/electrospray ionization-mass spectrometry(on-line trapping/cHILIC/MS) method for sensitive and simultaneous quantification of RNA modifications of N^6-methyladenosine(m^6A) and 5-methylcytosine(5-mC) from human blood. The hydrophilic organic-silica hybrid monolith was prepared using sol-gel combined with "thiol-ene" click reaction for the separation of nucleosides. A poly(MAA-co-EGDMA) monolithic capillary was used as the on-line trapping column.With the developed on-line trapping/cHILIC/MS analytical platform, the detection limits of m^6A and 5-mC can reach to 0.06 fmol and 0.10 fmol. We then investigated the contents of m^6A and 5-mC in human blood RNA from healthy persons at the age of 6-14 and 60-68 years. Our results showed that both m^6A and 5-mC contents were significantly decreased in elder persons, suggesting the RNA modifications of m^6A and 5-mC are correlated to aging.

乳制品中A1β-酪蛋白、A2β-酪蛋白检测方法研究进展

随着消费者对A2β-酪蛋白的关注度提升,A2β-酪蛋白相关产品不断更新换代。A2β-酪蛋白常用检测方法有反相高效液相色谱法(RP-HPLC)、液相色谱-高分辨串联质谱法、毛细管区带电泳法、试剂盒检测法等。本文对β-酪蛋白遗传变体A1β-酪蛋白和原始形态A2β-酪蛋白的功能特点、检测方法、定量分析进行综述,说明检测方法的原理和试剂药品的作用机理,加强对A1β-酪蛋白、A2β-酪蛋白检测方法的改进与优化,为A2β-酪蛋白应用于功能性食品、婴幼儿配方食品提供理论依据。

离子液体在色谱中的应用

离子液体是当前化学研究领域的一个热点,它在化学的各个领域都有研究和应用。该文就离子液体在毛细管电泳、气相色谱、高效液相色谱中的应用研究进展进行了较为详细的评述,对离子液体的分离检测作了简单的介绍,并对离子液体在色谱研究应用中的发展进行了展望。

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。

手性毛细管电色谱拆分比索洛尔、阿替洛尔、克仑特罗和特布他林

以万古霉素(vancomycin)毛细管柱为手性分离色谱柱,采用CLC和pCEC方法,对比索洛尔、阿替洛尔、克仑特罗和特布他林进行了手性拆分研究。在CLC方法中,上述4种物质均在甲醇/异丙醇/三乙胺/冰醋酸(60/40/0.05/0.1,V/V)条件下获得最大分离,分离度(Rs)分别为1.9、1.4、1.1和0.9。在pCEC方法中,采用极性有机模式时,Rs分别为1.9、1.4、1.5和1.5;采用反相模式时,Rs分别为2.0、1.7和1.2,而特布他林则未获分离。该方法能有效拆分比索洛尔、阿替洛尔、克仑特罗和特布他林,而且CLC、pCEC极性有机模式和pCEC反相模式之间有着较强的互补关系。

以聚乙二醇/甲醇为二元致孔剂的新型磺酸甜菜碱型两性离子亲水毛细管整体柱的合成与色谱评价

使用新型二元致孔剂聚乙二醇(PEG)/甲醇,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,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。对各反应物的配比进行了优化。结果表明,当单体与致孔剂的质量比为1∶2.5,并且致孔剂中PEG与甲醇的质量比为1∶2,单体内部SPP与PETA的质量比为1∶1,AIBN为总质量的0.1%时为最优配比;PEG/甲醇二元致孔剂的加入实现了对整体柱内部孔径大小的调节,得到了结构更为均一,渗透性、机械稳定性良好的毛细管整体柱,并且理论塔板数与传统制备方法相比有显著提高,在毛细管液相色谱模式下最高可达2.4×105塔板/m。将制备的整体柱应用于毛细管液相色谱和加压毛细管电色谱分离酚类、核苷类等极性小分子混合物,得到了很好的分离效果。

室温离子液体在分离分析中的应用

室温离子液体是指室温或接近室温下全部由离子组成的有机液体物质,具有不挥发,不易燃,溶解范围大,对空气和热稳定等特点,作为一种“可设计”型的环境相对友好溶剂,已被成功应用于分离分析领域中。本文重点综述了离子液体近年来在毛细管电泳、液相色谱及气相色谱中的应用进展,也对离子液体在质谱和光谱中的应用作了介绍。

毛细管电泳法测定性保健品中的西地那非

用毛细管电泳法测定了万艾可片剂和两种市售性保健品中的西地那非。以 6 0mmol/L磷酸二氢钠溶液为缓冲溶液 (pH 5 0 ) ,在 35℃ ,30kV的条件下进行测定 ,结果西地那非的质量浓度为 0 0 7g/L～ 1 0 5 g/L时与相应峰面积的线性关系良好 (r =0 9985 ) ;在实际样品中的平均回收率为 97 4 % ;方法的重现性好 ,峰面积的RSD为4 7%。与目前通行的高效液相色谱法测定西地那非的结果相比 ,毛细管电泳方法所测得的结果同样准确可靠 ,而且样品处理简便 ,测试时间短 ,测试成本低 。