色谱最新进展

1可媲美二维液相色谱-质谱联用技术的一维毛细管液相色谱-串联质谱技术 如今二维鸟枪式(shotgun)液相色谱结合串联质谱用于蛋白质组学的研究屡见报道,通常使用反相液相色谱和其他可以正交的分离模式联用结合串联质谱可以分离上千种蛋白质。由于整体硅胶柱具有优越的渗透性,因此其可以长柱形式实现高效分离;结合平缓的梯度洗脱可以分离高复杂性的样品。日本Keio University的Yasushi Ishihama等成功地将整体硅胶柱应用于一维液相色谱-串联质谱 (LC-MS/MS)中,鉴定了大肠杆菌细胞表达的蛋白质组。他们使用的是一根长350 cm、内径100 μm的整体硅胶-C18毛细管柱来进行鸟枪式蛋白质组分析。实验中将4 μg大肠杆菌的胰蛋白酶酶解物进样至整体柱,随后启动一个长达41 h的梯度程序,采用流量为500 nL/min、压力不超过20 MPa的非超高压液相色谱条件,最终大肠杆菌中2602种蛋白质(包括830种膜蛋白)的22196条非冗余肽段得到了鉴定。相比使用传统的15 cm长、3 μm粒径的C18硅胶填充柱的LC-MS/MS,该体系可以获得较之平均高约5倍的峰响应值。如此高的响应值可能是因为使用长的整体硅胶柱以及缓慢的梯度获得的高效分离大大降低了电离抑制影响的缘故。因为这个高分辨率的体系不需要任何预分离,这种单次蛋白质组学检测方法可以大大地简化鸟枪技术的工作量,也降低了所需样品量,虽然采用了长时间的缓慢梯度,但是仍然减少了总的分析时间。(来源: Anal. Chem., 2010, 82: 2616-2620) 2纳米结构启动质谱技术 质谱在检测生物分子方面有很大的潜力,但现有方法仍存在灵敏度不够高、需要基质分子促使分析对象发生离子化等缺陷。纳米结构启动质谱(nanostructure-initiator mass spectrometry, NIMS)技术使用纳米结构表面的“启动子”或者“笼状物”进行释放和离子化吸附在其表面的完整分子,能以极高的灵敏度分析非常小的区域,从而允许对肽阵列、血液、尿和单个细胞进行分析,而且还能用于组织成像。此技术克服了一般质谱方法灵敏度低和需要基质辅助离子化的缺陷。近几年,来源于动植物油脂及微生物代谢的生物柴油因其具有广泛的适用性而受到关注。由于柴油的品质与其脂肪酸的含量和性质密切相关,因此建立与当今代谢工程匹配的最佳脂肪酸克隆体高通量分析方法是生物柴油发展的关键。Wolfgang Reindl和Trent R. Northen将NIMS技术作为一种快速简便的分析手段用于植物及微生物脂肪酸的分析。研究证明,NIMS技术在负离子模式下可实现大量饱和及不饱和脂肪酸的直接检测,并且在几个数量级范围表现出良好的线性关系,检出限可达fmol级;另外,可以实现微量橄榄油、黄豆油和藻类短杆菌肽的定性及定量分析。NIMS的独特表面允许样品进行原位净化,这使得信噪比可以达到10倍以上。这项研究为植物及微生物油脂的快速分析奠定了基础,促进了生物柴油的发展。(来源: Anal. Chem., Article ASAP DOI: 10.1021/ac100159y, Publication Date (Web): March 31, 2010, in press) 3在线毛细管电泳-激光诱导荧光检测-多级质谱(CE-LIF-MSn)技术用于母乳喂养婴儿的食用母乳和粪便中寡聚糖图谱的建立 CE-LIF常被用在碳水化合物的检测分析中。没有紫外吸收的碳水化合物经过衍生可以在很低浓度水平被检出,灵敏度可达到pmol,所以在复杂生物样品的检测中CE-LIF备受关注。但是对检出物质进行确认却是一个复杂和耗时的过程。CE-MS则在物质鉴定方面有独特的优势。荷兰Wageningen University的Henk A. Schols教授课题组将在线CE-LIF-ESI(电喷雾离子源)-MSn用于母乳喂养婴儿的 食用母乳和粪便中的寡聚糖图谱的建立。LIF通过CE毛细管上的窗口进行柱上检测,毛细管中的液体通过一个鞘流接口进入到MS中。这种设计可以在同一次分析中既得到LIF信号又得到离子强度信号,并可将两组信号进行相关分析以进行物质确证。通过在线CE-LIF和ESI-MS串联对母乳喂养婴儿所食的母乳和其粪便中8-氨基芘-1,3,6-三磺酸钠盐(APTS)衍生的人乳低聚糖物质(HMOs)分析图谱的比较,对HMOs在胃肠道中的代谢有了进一步的认识。与母乳中的寡聚糖相比,在母乳喂养婴儿的粪便中确证了lacto-N-fucopentaose (LNFP)和lacto-N-neo-tetraose(LnNT)两种新的异构体。通过粪便中的寡聚糖图谱可以推断出高相对分子质量的HMOs在胃肠道中的生物转化和降解。(来源: Electrophoresis, 2010, 31: 1264-1273) 4动态针捕集技术在临床呼气试验中的应用 现代分析科学为各领域的实际应用提供了有效的途径和手段,在医药学领域,使用超痕量分析对人呼气中存在的挥发性生物标志物或药物进行检测的新型诊断方式便是一例。德国罗斯托克大学的Maren Mieth等曾提出个性化的动态针捕集技术用于呼吸气体的取样和富集(见: Anal. Chem., 2009, 81: 5851-5857)。动态针捕集技术利用装有吸附填料的捕集针对所要分析的气体进行采集,在样品处理方面较之固相萃取或者固相微萃取技术更加快速、灵敏、稳定、即时。最近,他们又首次在医疗机构的临床条件下,针对低量(20 mL)呼出气体,完成了多床层动态针捕集联合中心切割气相色谱/质谱法(GC/MS)和全二维气相色谱/飞行时间质谱法(GC×GC/TOF-MS)的分析。为了实现快速有效的分离分析,他们应用高通量自动化解吸和分离系统,采用22根不锈钢针（60 mm×0.41 mm i.d., 0.72 mm o.d.）捕集气体,针管吸附物可稳定存在约7.8 h。实验中首先建立中心切割GC/MS方法,在消除了高浓度的挥发性消毒剂和麻醉剂的背景干扰后,采用该体系成功地测定了11位接受心脏手术病人的呼出气体,找出了5种病人呼出物随时间变化(术前、 术后各时间点)的规律,显示了此方法具有作为判断病情发展的辅助手段的良好潜力。接下来又采用GC×GC/TOF-MS对被分析物进行无偏向性的筛查和鉴定,从一位麻醉后病人呼出物的分析结果可以看出,采用该方法能检测到超过200种物质,并可成功地鉴定其中的60种。因此,可将检测结果作为进一步筛查标志物的依据和基础。此项研究表明了动态针捕集技术结合色谱-质谱联用能够为临床呼气试验提供特定的解决问题的途径。(来源: Anal. Chem., 2010, 82: 2541-2551) 5采用小分子作为亲和色谱配体纯化蛋白质的新方法 亲和色谱(AC)是目前进行蛋白质纯化的最有效的色谱分离技术,但现有配体基本上是蛋白质,使该技术的使用范围受限,同时又具有价格昂贵和易降解的缺点。采用化学稳定的小分子配体将大大扩大AC在生物药品净化上的使用范围,但设计能与大分子蛋白质紧密并特异性结合的小分子存在很大的技术难度。丹麦University of Copenhagen的J. E. Rasmussen和K. J. Jensen等报道了一个完 整的用于开发和建立新型小分子亲和树脂的综合方法。该方法组合了虚拟筛选和颗粒上自动串行库筛选,其中使用了一种新的光编码方案促进结构的全面完整的“一珠一化合物”库的亲和力映射。他们用该方法制备了用于识别人生长激素(hGH)的小分子亲和树脂,并评价其对大肠杆菌裂解液中hGH的选择吸收和洗脱能力,hGH的纯度(91%)和回收率(61%)均较好。(来源: Angew. Chem. Int. Ed., published online: 18 Mar, 2010)     

快速色谱

基于柱液相色谱和薄层色谱之间的关系,讨论如何为快速色谱选择流动相,并介绍此技术手工操作的步骤.     

离子色谱

离子色谱(以下简称IC)是最近几年在美国Dow化学公司发展起来的一种新技术。1977年仪器开始作为商品出售。它使用离子交换原理,用抑制柱扣除淋洗液的本底电导,用电导法检定。IC可以快速,同时测定多组分,特别是目前难以用其它仪器,如原子吸收、光谱、极谱、X-荧光等测定的pK小于7的阴、阳离子,主要是阴离子。例如在十几分钟内可同时分离和测定F~-、Cl~-、NO_2~-、PO_4~(3-)、Br~-、NO_3~-、SO_4~(2-)等阴离子和Na~+、NH_4~+、K~+等阳离子。几种阴离子和阳离子的标准IC图见图1(A、B)。样品一般     

离子色谱重叠色谱峰的处理

介绍通过信号微分处理分辨离子色谱中重叠峰的方法。实验将Ｆ＾－、Ｃｌ＾－、Ａｃ＾－、ＮＯ＾－２、ＮＯ＾－３、ＰｈＣＯＯ＾－、山梨酸根和葡萄糖酸根等常见离子分组按一定比例混合,对重叠峰进行微分处理,得到的微分谱图可由峰高定量,收到了较好的效果。     

离子色谱不对称色谱峰的处理

介绍了通过微分处理分辨离子色谱中不对称峰的方法。实验将Ｆ＾－、Ｃｌ＾－、Ａｃ＾－、ＮＯ２＾－、ＮＯ３＾－、ＰｈＣＯＯ＾－、ＳＣＮ＾－、柠檬酸根、水杨酸根、山梨酸根和葡萄糖酸根等常见离子按一定比例配合混合液,对出现的不对称峰进行微分处理,得到的导数谱图可进行峰高定量,收到了较好的效果。     

气相色谱和液相色谱微型化中的关键问题

目前分析仪器微型化的浪潮汹涌澎湃,人们以极大的热情投入到这个浪潮中。从世界各地的实验室里出现的原理型样机看上去是如此的微小、简洁和令人惊诧,有如此多的加工工艺可以应用在微型器件的加工和组合上从非常昂贵的、在超净房间才能使用的精密仪器设备和工艺到土法上马、在普通房间就能操作的加工手段。它的前景是那样的诱人,引无数英雄一试身手。　　从1986年我第一次听说微型气相色谱仪并看到相关文章,就认定它是色谱发展的未来。1987年底我在荷兰第一次看到它时,就下决心今生一定研究微型色谱,因为它从观念上、认识上打开了分析仪…     

气相色谱一四温裂解气相色谱联用仪

本文用四个并联的蒸气相裂解器在气相色谱—裂解气相色谱联用装置,四个裂解器的温度为406.554,658及768℃,解决了实用的气相色谱—裂解气相色谱联用分析要求有普遍适用的裂解温度的问题,同时得到较多较大的裂解色谱峰,使定性更加准确。     

用台式色谱-质谱仪同时进行原油芳烃色谱和色谱-质谱分析

 摘要：用HP6890GC/5973MSD仪器,一次进样同时测定原油、烃源岩抽提物中芳烃馏分的芳烃色谱和色谱-质谱信息,效果良好,在有机地球化学研究工作中很有实用价值,方法具有高效、经济等优点。     

气相色谱与液相色谱保留值的换算方法

根据色谱热力学理论,在色谱保留值公式统一形式的基础上导出了气相色谱保留系数（I）与反相液相色谱保留公式参数a,c之间的关系式,证明结构类似化合物的a,c值与保留指数呈线性关系,同时存在氢键作用能、偶极矩作用的影响,从而提出了色相色谱与反相液相色谱保留值换算的方法;该理论为氯代芳烃的文献数据所证实。     

Preparative isolation and purification of amides from the fruits of Piper longum L. by upright counter-current chromatography and reversed-phase liquid chromatography

A versatile counter-current chromatography (CCC) with upright type-J multilayer coil planet centrifuge, named upright CCC, was applied to the isolation and purification of amides from Piper longum L., which is widely used as an anodyne and a treatment for stomach disease in China. After the saponification by KOH of the ethanol extracts solution of 15 kg of crude drug "Piper Longi Fructus", the fruits of P. longum L., the solution was extracted with light petroleum and 500 g of red crude oil was obtained. Using 2.5 g of red crude oil as sample, the preparative upright CCC with a two-phase system composed of light petroleum (bp 60-90 degrees C)-ethyl acetate-tetrachloromethane-methanol-water (1:1:8:6:1, v/v) was successfully performed, which yielded nine fractions. Then these fractions were further purified by use of reversed-phase liquid chromatography (RPLC) with a glass column of 500 x 10 mm i.d. packed with reversed-phase silica gel. As a result, nine target amides with over 95% purity, i.e., 50 mg of (2E,4E)-N-isobutyl-eicosa-2,4-dienamide, 150 mg of (2E,4E,14Z)-N-isobutyl-eicosa-2,4,14-trienamide, 110 mg of (2E,4E,12Z)-N-isobutyl-ocatadeca-2,4,12-trienamide, 50 mg of guineensine, 60 mg of pipernonaline, 75 mg of pellitorine, 63 mg of piperine, 45 mg of piperanine, and 40 mg of piperlonguminine were isolated, respectively. Structures of all compounds were identified by electrospray ionization MS, electron impact ionization MS, one- and two-dimensional NMR spectra.     

应用新型立式逆流色谱制备分离南蛇藤中的南蛇藤素

A versatile countercurrent chromatography with upright multilayer coil planet centrifuge, named upright countercurrent chromatography (UCCC), was applied to the isolation and purification of celastrol from the roots of Celastrus orbiculatus Thunb. The crude celastrol was obtained by elution with petroleum ether from ethanol extracts using a 15 cm length and 5 cm I.D. of silica gel flash chromatography. Preparative UCCC (Fig. 1) with a two-phase system composed of petroleum ether (b. p. 60 ～ 90 ℃ )-ethyl acetate-tetrachloromethanemethanol-water ( 1:1:8:6: 1, v/v) was successfully performed, yielding 705 mg celastrol at 99.5 % purity from 1020 rng of the crude extract in one step separation.     

Preparative isolation and purification of two amides from Mallotus lianus Croiz by high-speed counter-current chromatography

High-speed counter-current chromatography (HSCCC) was applied to the preparative isolation and purification of two amides from Mallotus lianus Croiz. In a single HSCCC separation, using the two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (5:1:5:1 v/v), 247.5 mg of the enriched crude sample was separated to afford 10.3 mg of N-isobutyl-2E,4E,12Z-octadecatrienamide and 15.7 mg of (7Z,10Z,18Z)tricosa-7,10,18-trienamide, a novel compound, with the purities of 98.0 and 94.6%, respectively. The HSCCC fractions were analyzed by HPLC and chemical structures of the compounds were identified by 1D- and 2D-NMR, ESI-, and GC-MS.     

New insecticidal amides from petroleum ether extract of dried Piper nigrum L. whole fruits

The petroleum ether extract of dried ground whole fruits of Piper nigrum L. afforded 20 compounds (1-20) including two new insecticidal amides named as pipnoohine (1), and pipyahyine (2), seven reported for the first time from this plant (12, 13, 15-17, 19, 20), and eleven known compounds (3-11, 14, 18). The structure of 1 has been elucidated as (2E,4E,12Z)-N-(4-methylpentyl)octadeca-2,4,12-trienamide and that of 2 as (2E,4E,11E)-12-(benzo[1,3]dioxol-5-yl)-N-(3-methylbutyl)dodeca-2,4,11-trien-amide through extensive ID-, 2D-NMR spectral studies and chemical reactions. The known compounds have been identified through comparison of their spectral data with those reported in literature. 1 and 2 exhibited toxicity at 35.0 and 30.0 ppm respectively against fourth instar larvae of Aedes aegypti L. by WHO method.     

Separation of six xanthones from Swertia franchetiana by high‐speed countercurrent chromatography

In our present study, two groups of xanthones isomers (1‐hydroxy‐3,5,8‐trimethoxyxanthone and 1‐hydroxy‐3,7,8‐trimethoxyxanthone; 1,8‐dihydroxy‐3,7‐dimethoxyxanthone and 1,8‐dihydroxy‐3,5‐dimethanolxanthone) and other two xanthones (3‐methoxy‐1,5,8‐trihydroxyxanthone and 3,5‐dimethoxy‐1‐hydroxyxanthone) were separated from Swertia franchetiana . First, a solvent system composed of petroleum ether/methanol/water (2:1:0.6, v/v) was developed for the liquid–liquid extraction of these xanthones from the crude extract. Then, an efficient method was established for the one‐step separation of these six xanthones by high‐speed countercurrent chromatography using n‐hexane/ethyl acetate/methanol/ethanol/water (HEMEW; 6:4:4:2:4, v/v) as the solvent system. The results showed that liquid–liquid extraction could be well developed for efficient enrichment of target compounds. Additionally, high‐speed countercurrent chromatography could be a powerful technology for separation xanthones isomers. It was found ethanol could be a good methanol substitute when the HEMEW system could not provide good separation factors.     

An efficient high‐speed countercurrent chromatography method for preparative separation of javanicin from Fusarium solani,a fungus isolated from the fruiting body of the mushroom Trametes trogii

To develop an efficient method for large preparation of javanicin from Fusarium solani, a rapid and simple method by high‐speed countercurrent chromatography was established based on average polarity (P′ values) and partition coefficients (K values) of crude samples. A suitable solvent system for high‐speed countercurrent chromatography was selected from many possible biphasic solvent systems. HSCCC was successfully applied to separate and purify javanicin, the main bioactive component of solid cultures of the fungus F. solani isolated from the fruiting body of Trametes trogii, with petroleum ether–ethyl acetate–methanol–water (4:3:2:1, v/v) as solvent system. A total amount of 40.6 mg of javanicin was obtained from 100 mg crude sample. The purity of javanicin was 92.2% with a recovery of 95.1%, as determined by high‐performance liquid chromatrography. The molecular structure was identified primarily by NMR and MS methods. The results indicated that high‐speed countercurrent chromatography could be a powerful technology for separating naphthoquinones from the solid cultures of the fungus F. solani. It is also of significance that the separation of javanicin from natural source was carried out for the first time utilizing high‐speed countercurrent chromatography.     

Preparative isolation and purification of two phenylbutenoids from the rhizomes of Zingiber cassumunar by upright counter-current chromatography

Two phenylbutenoids, (E)-4-(3',4'-dimethoxyphenyl)but-3-enyl acetate and (E)-4-(3',4'-dimethoxyphenyl)but-1,3-diene, were separated from the rhizomes of Zingiber Cassumunar using a preparative upright counter-current chromatography (CCC). With a two-phase solvent system composed of light petroleum (b.p. 60-90 degrees C)-ethanol-diethyl ether-water (5:4:2:1, v/v), 150 mg of (E)-4-(3',4'-dimethoxyphenyl)but-3-enyl acetate and 175 mg of (E)-4-(3','-dimethoxyphenyl)but- 1,3-diene with the purity of 98.7 and 95.1%, respectively, were obtained from 600 mg of the crude sample of Z. Cassumunar in a single-step separation. Structures of these two compounds were identified by ESI-MS, 1H NMR and 13C NMR.     

Isolation and purification of alkaloids from lotus leaves by ionic‐liquid‐modified high‐speed countercurrent chromatography

An effective high‐speed countercurrent chromatography method was successfully established by using ionic liquids as the modifier of the two‐phase solvent system. Adding a small amount of ionic liquids significantly shortens the separation time and improves the separation efficiency. The conditions of ionic‐liquid‐modified high‐speed countercurrent chromatography including solvent systems, types and content of added ionic liquids, and ionic liquids posttreatment were investigated. The established method was successfully applied to separate alkaloids from lotus leaves using a two‐phase solvent system composed of petroleum ether/ethyl acetate/methanol/water/[C₄mim][BF₄] (1:5:1:5:0.15, v/v/v/v/v). Four alkaloids pronuciferine (1.7 mg), N‐nornuciferine (4.3 mg), nuciferine (3.1 mg), and roemerine (2.1 mg) were obtained with the purities of 90.53, 92.25, 99.86, and 98.63%, respectively, from 100 mg crude extract of lotus leaves. The results indicated that the ionic‐liquid‐modified high‐speed countercurrent chromatography method was suitable for alkaloid separation from lotus leaves and would be a promising method for the separation of alkaloids from other natural products.     

Preparative isolation and purification of celastrol from Celastrus orbiculatus Thunb. by a new counter-current chromatography method with an upright coil planet centrifuge

A new counter-current chromatography (CCC) method with an upright coil planet centrifuge, which holds four identical multilayer coil columns in the symmetrical positions around the centrifuge axis, was applied to the isolation and purification of celastrol from the roots of Celastrus orbiculatus Thunb. The crude celastrol was obtained by elution with light petroleum from ethanol extracts using 15 cm x 5 cm i.d. silica gel flash chromatography. Preparative CCC with a two-phase system composed of light petroleum (bp 60-90 degrees C)-ethyl acetate-tetrachloromethane-methanol-water (1:1:8:6:1, v/v) was successfully performed, yielding 798 mg celastrol at 99.5% purity from 1020 mg of the crude sample in one step separation.     

An effective high-speed countercurrent chromatographic method for preparative isolation and purification of mollugin directly from the ethanol extract of the Chinese medicinal plant Rubia cordifolia

The medicinal plant Rubia cordifolia has been used widely in traditional Chinese medicine (TCM) for its antibacterial, antioxidant and anti-inflammatory activities. In this study, a preparative high-speed countercurrent chromatography (HSCCC) method for isolation and purification of the bioactive component mollugin directly from the ethanol extract of R. cordifolia was successfully established by using light petroleum (bp 60-90 degrees C)/ethanol/diethyl ether/water as the two-phase solvent system. The upper phase of light petroleum/ethanol/diethyl ether/water (5:4:3:1 v/v) was used as the stationary phase of HSCCC. Under the optimum conditions, 46 mg of mollugin at 98.5% purity, as determined by HPLC, could be yielded from 500 mg of the crude extract in a single HSCCC separation. The peak fraction of HSCCC was identified by 1H NMR and 13C NMR.