高效液相色谱-电喷雾质谱联用分析PPMP衍生化的壳寡糖

以1-(4-异丙基)苯基-3-甲基-5-吡唑啉酮(PPMP)为衍生化试剂在氨水介质中对壳寡糖链进行衍生化,衍生化产物用RP-HPLC分离和ESI-MS分析。结果表明在确定的衍生化条件下,PPMP和壳寡糖的衍生化产物主要为单分子衍生物,此单分子PPMP衍生物在ESI-MS的正负离子模式下均有较好的响应,并且在RP-HPLC柱上能够实现很好的分离。据此建立了PPMP柱前衍生HPLC/ESI-MS在线联用检测壳寡糖混合物组成的方法。该法可作为壳寡糖样品在质量控制、构效关系研究等方面的方法参考。     

3-氨基-9-乙基咔唑衍生化寡糖混合物的高效液相色谱分离及激光解吸电离飞行时间质谱分析

建立了以3-氨基-9-乙基咔唑(AEC)为衍生化试剂对寡糖的标记方法。寡糖的还原端与AEC的伯氨基反应生成烯胺,再被NaBH3CN还原为二级胺,使得寡糖被AEC标记。衍生物通过反相高效液相色谱分离纯化,采用的色谱柱为Waters Symmetry C18柱(3.9 mm×150 mm,5 μm),乙腈和乙酸铵水溶液(pH 4.5)为流动相,梯度洗脱,在254 nm波长处检测,并以基质辅助激光解吸电离飞行时间质谱进行分析。在此衍生化条件和色谱条件下,葡寡糖衍生物分离良好,并且AEC衍生可显著提高葡寡糖的质谱检测灵敏度。该方法适用于寡糖的分离纯化和结构分析,并与生物质谱具有良好的兼容性,表明该方法在微量寡糖链分析方面有广阔的应用前景。     

1-苯基-3-甲基-5-吡唑啉酮衍生中药寡糖的毛细管区带电泳分离

建立了一种可用于中药寡糖分离的毛细管区带电泳(CZE)分析方法。分离条件: 未涂层熔融石英毛细管柱(48 cm×50 μm,有效长度38 cm),紫外检测波长245 nm,采用1-苯基-3-甲基-5-吡唑啉酮(PMP)为寡糖衍生试剂,50 mmol/L磷酸盐溶液(pH 2.5)为运行缓冲液,电压15 kV,重力进样10 cm×2 s。针对中药寡糖实际样品的复杂性,通过添加多种常见单糖进行方法的实用性验证,并且将方法用于板蓝根多糖的控制降解产物的分离。结果表明,板蓝根寡糖组分可按相对分子质量从小到大的顺序分离,分离效果令人满意。该分离方法操作简单、高效,可用于中药寡糖实际样品分析。另外,还对单糖、寡糖PMP衍生物的电泳迁移行为进行了初步的理论探讨。     

寡糖衍生化及基质辅助激光解吸电离飞行时间质谱分析方法研究

为提高中性寡糖在基质辅助激光解吸电离飞行时间质谱(MALDI-TOF)中的检测灵敏度,建立了以1-(4-氰基苯基)-4-哌啶碳酰肼(CPH)为衍生化试剂对寡糖的标记方法。寡糖的还原端与CPH的酰肼基团反应生成腙,使得寡糖被CPH标记,衍生物以MALDI-TOF质谱进行分析。结果表明:在反应温度95℃,醋酸浓度为0.125%(V/V),CPH过量100倍的条件下,衍生产率可达最大,并且CPH衍生可使中性寡糖在MALDI-TOF质谱中的检测灵敏度提高10倍。本方法简便快速,灵敏度高,适合微量寡糖链的质谱分析。     

荧光辅助糖电泳用于果胶水解产物中寡糖的分析研究

荧光辅助糖电泳(FACE)是首先用荧光衍生化试剂对糖类分子的还原端进行衍生化标记, 然后在一定浓度的聚丙烯酰胺凝胶上进行分离的分析方法, 可同时分析中性糖与酸性糖. 将该方法用于果胶寡糖的分离分析, 对影响FACE的诸多因素如荧光试剂的种类、用量, 荧光衍生化时间、温度, 分离胶浓度及盐、酸等进行了考察, 对果胶寡糖的FACE条件进行了优化, 结果显示: 每1.2 mg无酸且不含盐的果胶寡糖中, 加入0.2 mol/L的ANTS溶液3.75 μL, 1.0 mol/L的NaBH3CN溶液5 μL, 40 ℃衍生化反应16 h后, 在浓度为38%的分离胶上电泳分离, 取得良好的分离效果. 在该实验条件下, 果胶多糖酸水解后得到聚合度为2～16的果胶寡糖混合物, 与质谱分析结果基本一致. 该方法快速、简捷、灵敏、分辨率高, 费用低, 为果胶多糖可控性降解的监测和果胶寡糖的分离分析提供了技术手段.     

κ-卡拉胶寡糖AEC柱前衍生物的LC-ESI-MS/MSn分离分析

以κ-卡拉胶为原料, 经盐酸水解得到一系列寡糖混合物. 以3-氨基-9-乙基咔唑(3-amino-9-ethylcarbazole, AEC)为衍生化试剂, 对酸解得到的κ-卡拉胶寡糖进行柱前衍生, 采用反相C₁₈色谱柱(250 mm×4.6 mm, 5 μm), 乙腈和乙酸铵水溶液(pH 4.5)为流动相, 梯度洗脱, 在254 nm波长处检测, 建立了κ-卡拉胶寡糖衍生物的高效液相色谱(HPLC)分离以及液相色谱-电喷雾质谱联用(LC-ESI-MS)分离分析的方法, 并对AEC衍生后的κ-卡拉胶寡糖进行多级质谱裂解(MSⁿ), 进一步获得了κ-卡拉胶寡糖的结构信息. 该方法对κ-卡拉胶寡糖的结构分析、构效关系等方面的研究有参考价值.     

液相色谱-电喷雾-四级杆-飞行时间质谱法分析琼胶寡糖

建立超高效液相色谱-电喷雾-四级杆-飞行时间质谱联用技术快速分离鉴定琼胶寡糖的方法.通过分析比较3种色谱柱(BEH Amide、BEH C8及Atlantis T3)对琼胶寡糖的分离结果发现,Amide色谱柱具有最佳优势,在无需样品衍生的状态下,可使聚合度介于3～29的琼胶寡糖得以良好分离,分析迅速,灵敏度高.而衍生后...     

寡糖-8-氨基芘-1,3,6-三磺酸衍生物的毛细管电泳-激光诱导荧光分离

利用自组装的毛细管电泳-激光诱导荧光装置,研究了多种寡糖-8-氨基芘-1,3,6-三磺酸(寡糖-APTS)衍生物的分离.考察了电泳介质、浓度及pH对寡糖-APTS衍生物分离的影响,在酸性和碱性条件下,分别实现了痕量寡糖标准品及葡聚糖水解产物的高效分离     

高效液相色谱-质谱联用法分析3-氨基-9-乙基咔唑柱前衍生化壳寡糖

以3-氨基-9-乙基咔唑(3-amino-9-ethylcarbazole, AEC)为衍生化试剂对壳寡糖进行柱前衍生,壳寡糖(COS)的还原端与AEC的伯氨基反应生成烯胺,再被硼氢氰化钠(NaBH3CN)还原为二级胺。采用反相C18色谱柱(250 mm×4.6 mm, 5 μm),乙腈和乙酸铵水溶液为流动相(pH 4.5),梯度洗脱,在254 nm波长处检测,建立了一套壳寡糖衍生物的高效液相色谱(HPLC)分离分析、电喷雾质谱(ESI-MS)及液相色谱-电喷雾质谱联用(LC-ESI-MS)的分析方法。该方法操作简单、灵敏度高、重复性好,在COS的组分分析、质量控制及构效关系研究方面有潜在的应用价值。     

温和条件下柱前标记-高效液相色谱-质谱法测定枸杞多糖中单糖组成

基于高效液相色谱-质谱联用分析技术（HPLC-MS）,在温和的NH₃·H₂O条件下,采用1-苯基-3-甲基-5-吡唑啉酮（PMP）衍生化试剂成功地标记了果糖及多种醛单糖,同时提出了PMP标记果糖的衍生化机理。采用Kromasil-C18色谱柱（100 mm×4.6 mm,3.5 μm）分离,梯度洗脱,选择离子模式检测,建立了8种常见单糖标记物的结构确认及含量测定的分析方法。该方法在一定质量浓度范围内具有良好的线性（相关系数> 0.9947）,检出限为0.003~0.05 mg/L,定量限为0.01~0.15 mg/L。平均回收率为65.1%~116.2%,相对标准偏差≤10.2%（n=5）。自制4个产地枸杞多糖,对其单糖组成的分析结果表明,它们均由甘露糖、果糖、鼠李糖、半乳糖、葡萄糖、木糖、阿拉伯糖和脱氧核糖8种单糖组成,但各种单糖含量的分布有较大的差异。该法简便,灵敏度高,重复性好,可用于水热法水解枸杞多糖水解液中单糖标记物结构的确认及测定,对规范植物多糖的质量控制具有重要意义。     

改进的PMP柱前衍生化方法用于单糖的组成分析

用氨水替代NaOH溶液, 反应后氨水可通过减压干燥除去, 这样不仅简化了衍生化反应的后处理过程, 而且不影响衍生物的质谱分析, 省去了质谱分析前的脱盐处理过程. 本研究建立了5种常见单糖的分析分离模式, 对其进行质谱分析, 用所建立的方法对标准二糖及3种多糖样品中的单糖组成进行了分析, 取得了满意的结果.     

柱前衍生化高效液相色谱法分析多糖中的单糖组成

报道了多糖中单糖组成的柱前衍生化高效液相色谱测定方法。采用反向高效液相色谱250nm紫外检测和使用梯度洗脱，6种还原单糖的1－苯基－3－甲基－5－吡唑啉酮衍生实现了良好的分离并具有良好的峰形。对单糖组成的定量测定进行了方法学考察，建立了单糖组成分析的数据分析方法，并用所建立方法对一个多糖中的单糖组成进行了分析，获得良好的重复性。     

Evaluation of a new reagent: anthraquinone-2-sulfonyl chloride for the determination of phenol in water by liquid chromatography using precolumn phase-transfer catalyzed derivatization

A new reagent, anthraquinone-2-sulfonyl chloride, is used for the derivatizaton of phenols. Several compounds with different polarities are selected to evaluate the new reagent and derivatives of these phenols that are prepared via a facile pathway. The optimal conditions for analytical derivatization and mechanism of the derivatization reaction are discussed. The derivatization procedure involves an ion-pair extraction of the deprotonated phenols with a tetrabutylammonium counter ion in the organic phase. At the interface of two phases, the derivatization reaction occurs quantitatively at room temperature within 3 min. The derivatives are stable and readily amenable to analysis by normal-phase (NP) and reversed-phase (RP) high-performance liquid chromatography (HPLC). Excellent linearity response was demonstrated over the concentration range of 0.2-200 micromol/L at 320 nm for NP-HPLC and at 256 nm for RP-HPLC. Combined with preconcentration using a Waters Sep-Pak Plus C(18) cartridge, detection limits of phenols for water-sample analysis are as low as 1 x 10(-9) mol/L (approximately 0.1 microg/mL).     

Determination of Defibrase in Pharmaceutical Formulation by LC with 6-Aminoquinolyl-N-hydroxysuccinimidyl Carbamate Derivatization and Fluorescence Detection

A sensitive LC method with pre-column fluorescence derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate has been developed for the determination of defibrase from the venom of Agkistrodon acutus (also named defibrase in the Chinese Pharmacopoeia) in pharmaceutical formulation. By a denaturing procedure prior to derivatization, full and homogeneously derivatization of defibrase was obtained and demonstrated using MALDI-TOF-MS. The specificity of the method was validated by assessing interference from the placebo and by forced degradation. The method has demonstrated good linearity (r = 0.9998), accuracy (mean recovery 98.53%) and precision (RSD < 2.5%). Moreover, the method was found to be sensitive with a low limit of detection (3.35 ng mL^?1) and limit of quantitation (10.16 ng mL^?1). The method was successfully applied to the quantitative determination of defibrase in pharmaceutical formulation.     

柱前衍生高效液相色谱法分析海洋褐藻多糖药物的糖醛酸组成

采用三氟乙酸(TFA)分别将藻酸双酯钠(PSS)、甘糖酯(PMS)和古糖酯(PGS)3种海洋褐藻多糖药物进行降解,再与1-苯基-3-甲基-5-吡唑啉酮(PMP)进行柱前衍生,建立了3种药物糖醛酸组成分析的高效液相色谱方法.结果表明:PSS、PMS、PGS的最适降解条件:在110 ℃下降解6 h,TFA浓度3 mol/L;最适衍生条件:反应温度70 ℃,反应90 min,PMP与供试品的摩尔比为12∶ 1,NaOH与供试品的摩尔比为2∶ 1;色谱条件为:0.1 mol/L 磷酸盐(pH 6.7)缓冲液-乙腈(82∶ 18,V/V),检测波长:245 nm,流速:1 mL/min.在此色谱条件下,甘露糖醛酸(M)和古罗糖醛酸(G) 分离良好,测得PSS、PMS、PGS的M/G分别为2.37±0.05、6.60±0 22和0.22±0 03,该方法具有良好的精密度和重现性,灵敏度高,适合于海洋褐藻多糖类药物的微量分析.     

Complete separation of ephedrines by graphite-layer open-tubular (GLOT) column

Summary A reversed phase high performance liquid chromatographic (RP-HPLC) method for the analysis of amino acids in kelp, using precolumn derivatization, is described. Phenylisothiocyanate (PITC) was used as the reagent for derivatization. The kelp samples were prepared by microwave hydrolysis in only 5 min; seventeen PTC amino acids were separated after hydrolysis and derivatization within 12 min. The coefficients of variation were >1.94 and the correlation coefficients for concentration versus response were >0.999 for all derivatives. The ratio of branched amino acid (BAA) to aromatic amino acid (AAA) was also studied. The method has the advantage of shorter hydrolysis and analysis times with optimum separation. In addition, it gives high repeatability of retention times and peak areas for all the amino acids present.     

High-performance liquid chromatographic determination of (R)-and (S)-proxyphylline in human plasma

A reversed-phase high-performance liquid chromatographic assay has been developed for determination of (R)-(--)-and (S)-(+)-proxyphylline in human plasma. The procedure is based on liquid-solid extraction of proxyphylline from plasma followed by derivatization of extracted proxyphylline with (--)-camphanoyl chloride. The ratio between the enantiomers is calculated from the peak areas of the corresponding diastereoisomeric proxyphylline camphanates after injection into the liquid chromatograph. The recovery of proxyphylline from plasma was 88% (coefficient of variation = 4%) and proxyphylline was detectable from a plasma concentration of 0.2 micrograms/ml. Three different plasma extraction procedures for proxyphylline using Extrelut, Bond Elut, and Chem Elut columns have been developed and compared, and the rate of derivatization of the proxyphylline enantiomers with camphanoyl chloride has been studied.     

A rapid method for isolation and purification of an anticoagulant from Whitmania pigra

Whitmania pigra is common in China and has been used as a traditional Chinese anticoagulant medicine for years, but its effective components are unknown to scientists. In this article we report a rapid method for isolation and purification of an anticoagulant from W. pigra for the first time. An acetone-water extract of W. pigra was subjected to anion-exchange chromatography on a Sephadex DEAE A-50 column, and gel permeation chromatography on Sephadex G-25 and Sephadex LH-20 columns successively, which afforded a fraction with potent anticoagulant activity. An anticoagulant was isolated and purified from this fraction by reversed-phase high-performance liquid chromatography (RP-HPLC). It was identified as a single pure substance by RP-HPLC and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). This component was named whitmanin and its molecular weight was determined as 8608 Da by matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF-MS).     

Determination of trace biogenic amines with 1,3,5,7-tetramethyl-8-(N-hydroxysuccinimidyl butyric ester)-difluoroboradiaza-s-indacene derivatization using high-performance liquid chromatography and fluorescence detection

A reversed-phase high-performance liquid chromatographic method based on chemical derivatization with fluorescence detection has been developed for analyzing biogenic amines in food and environmental samples. A BODIPY-based fluorescent reagent, 1,3,5,7-tetramethyl-8-(N-hydroxysuccinimidyl butyric ester)-difluoroboradiaza-s-indacene (TMBB-Su), was employed for the derivatization of these biogenic amines at 20 °C for 20 min in pH 7.20 borate buffer after careful investigation of the derivatization conditions including reagent concentration, buffer solution, reaction temperature and reaction time. Separation of biogenic amines with gradient elution was conducted on a C8 column with methanol-tetrahydrofuran-water as mobile phase. The detection limits were obtained in the range from 0.1 to 0.2 nM (signal-to-noise=3). This procedure has been validated using practical samples. The study results demonstrated a potential of employing high-performance liquid chromatography (HPLC) with 1,3,5,7-tetramethyl-8-(N-hydroxysuccinimidyl butyric ester)-difluoroboradiaza-s-indacene labeling as a tool for quantitative analysis of biogenic amines involved in various matrices.