Chromatographic analysis of blood lipids. Comparison between gas chromatography and thin-layer chromatography with flame ionization detection

Intact human blood plasma lipids of different composition were analyzed by gas chromatography and thin-layer chromatography with flame ionization detection. The reproducibility of the results obtained by gas and thin-layer chromatography was compared. The main advantages and disadvantages of both methods for lipid analysis are discussed. Generally, the variability of the results measured by thin-layer chromatography in series and from day to day was greater than that obtained by gas chromatography.     

Elucidation of steroid glycosides in Anemarrhena asphodeloides extract by means of comprehensive two-dimensional reversed-phase/polyamine chromatography with mass spectrometric detection

In the work presented here, a novel approach to comprehensive two-dimensional liquid chromatography is evaluated. Reversed-phase liquid chromatography was employed for the first-dimension separation and polyamine chromatography was chosen for the second-dimension separation mode. The two dimensions are highly orthogonal and the separation efficacy of the developed octadecylsilica × polyamine was tested by separating an extract from Anemarrhena asphodeloides. The steroid glycosides identified by comprehensive two-dimensional liquid chromatography in this experiment were compared to those obtained for monodimensional liquid chromatography. The comprehensive two-dimensional liquid chromatography system, thanks to the complementary separation selectivity and enhanced peak capacity provided by the two columns, allowed to distribute five compounds of low amounts otherwise unachievable by monodimensional liquid chromatography. In addition, four steroid isomers with similar fragmentation characteristics in MS/MS spectra, were newly separated based on their different chemical structures.     

Performance of ion chromatography in the determination of anions and cations in various natural waters with elevated mineralization

The performance of ion chromatography in the determination of anions and cations in natural mineral waters of different composition and different total mineralization was evaluated. Up to 12 ions of the 20 usually included in extended chemical analysis of natural waters were successfully determined by ion chromatography alone. At least 98.60% and up to 99.96% of total cation composition of mineral waters was determined by ion chromatography. Hydrogen carbonate predominated in anion composition of mineral waters and was determined titrimetrically. The percentage of anions determined by ion chromatography in the remaining anion composition of mineral waters was between 98.90% and 99.96%. The agreement between total concentrations of anions and cations in individual mineral waters determined predominantly by ion chromatography is very good and the performance of ion chromatography for the basic and for the extended chemical analysis of highly mineralized water samples is very high. Method development was assisted by previously developed algorithms and appropriate experimental conditions are also discussed.     

烷基酚聚氧乙烯醚在不同液相色谱分离模式中的分离研究

考察了烷基酚聚氧乙烯醚在反相色谱、正相键合色谱、硅胶吸附色谱、体积排阻色谱4种不同液相色谱分离模式中的分离效果,分别采用Kromasil C_(18)(250 mm× 4.6 mm,5 μm)、Agilent ZORBAX NH2(250 mm× 4.6 mm,5 μm)、Waters Spherisorb S3W(150 mm×2.0 mm,3 μm)和Shodex MSpak GF-310 2D(150 mm×2.0 mm,5 μm)色谱柱,以225 nm为紫外检测波长,对不同液相色谱分离模式的流动相组成、梯度洗脱条件、柱温、流速等进行了优化,并对烷基酚聚氧乙烯醚在不同液相色谱分离模式中的保留机理进行了初步探讨.结果表明,正相键合色谱实现了烷基酚聚氧乙烯醚的最佳分离;硅胶吸附色谱和体积排阻色谱的分离效果较正相键合色谱稍差.     

Separation of the mineral oil aromatic hydrocarbons of three and more aromatic rings from those of one or two aromatic rings

An analytical method was developed for the quantitation of the mineral oil aromatic hydrocarbons in cosmetic raw materials separating those of one or two aromatic rings from those of three and more aromatic rings. Normal phase high performance liquid chromatography was used with donor‐acceptor complex chromatography. The composition of both fractions and the quantities of respective compounds were determined by comprehensive two dimensional gas chromatography with time of flight mass spectrometry and by liquid chromatography coupled to gas chromatography with flame ionization detection.     

多维液相色谱-质谱用于酶解猪血蛋白中活性肽的研究

以强阳离子交换柱（SCX）为一维色谱柱,反相柱（RP）为二维色谱柱,采用在线捕集接口形式,通过10通阀连接一、二维色谱柱,构建了二维液相色谱分离系统。将该系统用于酶解猪血蛋白中对血管紧缩素Ⅰ转移酶（ACE）具有活性抑制作用的肽进行分离、鉴定,共检测出104个组分。收集一维馏分,离线注入LC—MS,鉴定出其中含有SAL、DKF、ESF、STVL及FESF5个小肽。     

Off‐line comprehensive two‐dimensional reversed‐phase countercurrent chromatography with high‐performance liquid chromatography: Orthogonality in separation of Polygonum cuspidatum Sieb. et Zucc

Off‐line comprehensive two‐dimensional reversed‐phase countercurrent chromatography with high‐performance liquid chromatography was investigated in separation of crude ethanol extract from traditional Chinese medicinal herb Polygonum cuspidatum Sieb. et Zucc. Two‐dimensional contour plots for countercurrent chromatography with high‐performance liquid chromatography was obtained after comprehensive separation was completed. Total peak capacity was evaluated and approximately 810 peaks were obtained through a comprehensive two‐dimensional separation. A highly orthogonality of 52.23% and a large separation space occupancy of 88.86% were achieved. Meanwhile, it was found that several components could be well separated by countercurrent chromatography while they could not be separated by high‐performance liquid chromatography, and vice versa, which further indicated the orthogonality of the two separation methods. The off‐line comprehensive two‐dimensional countercurrent chromatography with high‐performance liquid chromatography provided a promising and powerful method for separation of complex natural products.     

疏水作用色谱法同时纯化及复性基因重组人干扰素-α

 使用高效疏水作用色谱直接从大肠杆菌表达的基因重组人干扰素 α(rhIFN α)包涵体的裂解液中纯化了rhIFN α ,并在纯化的同时获得了高的复性效率 ,使复性和纯化一步完成 ,大大地简化了操作步骤。用凝胶排阻色谱对该法纯化的rhIFN α进行了纯度测定 ,纯度达到 95 %以上。该法的活性回收率分别比稀释法和透析法高 1 0倍和 1 6倍。     

31ku激发子蛋白的液相色谱分离纯化

利用阴离子交换色谱和疏水相互作用色谱从烟草疫霉菌培养液中分离出一种新的31ku激发子蛋白，选择了阴离子交换色谱流动相的的最佳pH值6．0，建立了疏水相互作用色谱硫酸铵Tris缓冲液－水洗脱模式，简化了纯化步骤和减少了活性损失的危险。     

氧弹燃烧-离子色谱法测定煤中氯含量

建立了氧弹燃烧-离子色谱测定煤中氯含量的方法.在加有(NH4)2CO3溶液和过量氧气的氧弹中燃烧煤样,释放的氯被(NH4)2CO3溶液吸收,过滤溶液后, 采用离子色谱外标法测定滤液中氯的浓度,最后计算出煤中氯的含量.色谱工作条件:淋洗液为1.8 mmol/L Na2CO3与1.7 mmol/L NaHCO3混合液,流速1 mL/min;再生液为40 mmol/L H2SO4,流速0.5 mL/min;进样量20 μL.色谱标准工作曲线线性相关系数0.9996;10次测定1 mg/L Cl-标准溶液的均值为1.0012 mg/L,相对标准偏差为1.34%;8个煤样加标回收率为90.7%～104.3%;测定标准物质GBW11119 及GBW11120的相对误差分别为1.75%和1.36%;对比研究显示,氧弹燃烧-离子色谱测定8个煤样(除两个煤样外)氯含量结果远高于艾士卡剂混合熔样-离子色谱测定结果,表明艾士卡剂混合熔样过程由于煤样未处于完全密闭状态导致部分氯的散失.     

Column-switching high-performance liquid chromatographic detection of pholcodine and its metabolites in urine with fluorescence and electrochemical detection.

A sensitive and selective method for the detection of pholcodine and its metabolite morphine in urine using high-performance liquid chromatography is described. It involves on-line clean-up of urine on a trace enrichment column packed with a polymeric strong cation-exchange material. Pholcodine and its metabolites were separated on two analytical columns with different selectivities. Pholcodine was detected by a fluorescence detector and morphine was detected electrochemically. One system, based on reversed-phase chromatography, applied a polystyrene-divinylbenzene column and gradient elution. The other system was based on normal-phase chromatography with a silica column and isocratic elution. Morphine was confirmed to be a metabolite of pholcodine by reversed-phase chromatography and electrochemical detection. Two unidentified metabolites of pholcodine were separated from pholcodine by normal-phase chromatography and detected by fluorescence detection.     

A Novel Oligosaccharide from the Mucus of the Loach

A novel oligosaccharide was isolated and purified from the mucus of the loach, Misgurnus anguillicaudatus. Its was identified by several qualitative tests and characterized by elementary analysis,UV and IR spectrum. Its average molecular weight(Mw=1539.4) was determined by gel permeation chromatography. The major structural monomers of Misgurnus anguillicaudatus oligosaccharide were identified to be D-galactose and L-fucose by paper chromatography and gas chromatography.     

Purfication of synthetic cardiotoxin by affinity chromatography

A polypeptide containing 60 amino acids with 4 disulphide bonds, synthesized by the solid-phase method, was highly purifed by anticardiotoxin-Sepharose affinity chromatography following gel filtration and CM-cellulose chromatography. The identification of the final product as cardiotoxin was confirmed by thin-layer chromatography on silica gel, polyacrylamide gel electrophoresis, amino acid analysis, circular dichroism spectra, N-terminal analysis and four biological tests.     

Isolation and characterization of proteoglycans from different tissues

Two chromatographic procedures for the isolation and purification of proteoglycans (PG) and their related glycosaminoglycan (GAG) peptides are described. PG from human aorta were isolated from tissue extract by sequential ion-exchange, size-exclusion and hydroxyapatite chromatography. Final purification of samples was achieved by chromatography on Mono Q. Homogeneity of samples was demonstrated by Western blot analysis of biotin-labelled compounds prior to and after enzymatic digestion and dual-wavelength detection in size-exclusion chromatography. The purity of samples obtained by the procedure described was sufficient for protein sequence analysis. GAG preparations of bovine trachea cartilage were purified by the sequential use of strong anion-exchange supports. Molecular weight distribution and sensitivity to treatment with glycan-specific enzymes was shown by size-exclusion chromatography.     

Silver ion coordination countercurrent chromatography: Separation of β‐elemene from the volatile oil of Curcumae Rhizoma

In this work, the antitumor constituent β‐elemene was selectively separated from the volatile oil of the Curcumae Rhizoma by countercurrent chromatography with silver nitrate as selective reagent based on the formation of coordination complexes. A biphasic solvent system composed of n‐hexane/methanol/water (2:1.5:0.5, v/v/v) was selected, in which 0.15 mol/L of silver nitrate was added to the aqueous phase. The aqueous phase was used as the stationary phase for separation of β‐elemene by countercurrent chromatography after it was partially purified from the volatile oil by silica gel column chromatography. An enriched β‐elemene fraction was obtained by silica gel column chromatography to improve the percentage of β‐elemene from 16.5 to 46.1%. Subsequently, β‐elemene was further purified from 445 mg of the partially purified sample of volatile oil by countercurrent chromatography with silver nitrate as a selective reagent, yielding 145 mg of β‐elemene with greater than 99% purity, as determined by gas chromatography mass spectrometry. The recovery of β‐elemene from the crude volatile oil through two steps was around 63.6%.     

高效液相色谱-电喷雾质谱法用于茶多糖蛋白的纯度和相对分子质量的测定

应用Sephadex G100凝胶色谱方法从江西产粗老茶叶中提取纯化得到茶多糖蛋白(TGC)。通过高效液相色谱法对其纯度进行了分析,表明其为均一组分,进而应用凝胶法和高效液相色谱 电喷雾质谱法测得该茶多糖蛋白的相对分子质量为51 500。     

Porous structure of the monolithic sorbent and separation properties of monolithic capillary columns in gas and liquid chromatography

Macroporous polymer based on polydivinylbenzene was used for the preparation of monolithic capillary columns with the diameter from 0.01 to 0.53 mm for separations by gas and liquid chromatography. The separation properties of the columns were studied by analysis of model systems of aromatic (in liquid chromatography) and light (in gas chromatography) hydrocarbons. The permeability was determined and the C parameter of the Van-Deemter equation was found for each column. The permeability of the majority of columns determined by gas chromatography is independent of the column diameter. The permeability of the same columns in liquid chromatography is also almost constant for the columns 0.53–0.1 mm in diameter; however, the permeability decreases sharply on going to columns of smaller diameter. In gas chromatography the value of the C parameter reflecting the effect of the mass transfer of the sorbate between the mobile and stationary phases on the smearing of a chromatographic peak in the column approximately the same for all columns. In liquid chromatography the value of the C coefficient in the Van-Deemter equation for the same capillary columns changes with a change in the column diameter and reaches a minimum for the columns 0.1 mm in diameter. The differences observed for the characteristics of the columns in gas and liquid chromatography are due to different structures of the macroporous monolith formed in columns of different diameter and to the effect of solvation of the monolith by the mobile phase under the conditions of liquid chromatography.     

Reactions of polystyryl anions with carbon dioxide and oxygen. Analysis of products by silica gel chromatography

Polystyryllithium was prepared by anionic polymerization. This “living polymer” and the polystyrylmagnesium bromide derived from it were treated with carbon dioxide (solid or gas). The highest yields of carboxylic acid were obtained when solid carbon dioxide was used with polystyryllithium or by treatment of polystyrylmagnesium bromide with gaseous carbon dioxide. The products from the reaction of polystyryllithium with oxygen were polymeric ketone X, the alcohols IXa and IXb, and coupling products (e. g., XI). The various functionalized and unfunctionalized polystyrene products were isolated by chromatography on silica gel and were characterized by gel permeation chromatography (GPC), thin layer chromatography (TLC), and high-performance liquid chromatography (HPLC) in combination with chemical transformations.     

高活性燕麦蛋白源ACE抑制肽的制备、纯化及结构鉴定

利用胰蛋白酶水解燕麦蛋白制备了高血管紧张素转化酶(Angiotensin I-Converting Enzyme, ACE)抑制活性的燕麦蛋白酶解物, 分别采用离子交换色谱、凝胶过滤色谱和反相高效液相色谱等分离手段从酶解物中分离出一种新的强活性ACE抑制肽, 其IC50值为77.3 μmol/L; 通过基质辅助激光解析电离飞行时间串联质谱对其进行结构鉴定, 其氨基酸序列为Glu-Gly-Gly-Tyr-Arg.     

Simultaneous determination of serum uremic toxins, cations and anions and urea determination by post-column colorimetry using immobilized enzyme

A column-switching method which combines ion-exchange and ion-pair reversed-phase chromatography was developed for the determination of serum uremic toxins, cations and anions. Serum urea, which was poorly separated by reversed-phase chromatography, was analyzed using an immobilized-urease column and detected by post-column colorimetry. Apart from the simultaneous analysis, anion analysis using ion-pair reversed-phase chromatography on an ODS column was also developed. The origin of the system peak observed in anion analysis with an eluent containing phthalate has been clarified.