Rapid Sara Seprations by High Performance Liqid Chromatography

Abstract

This paper presents both rapid analytical and preparative high performance liquid chromatographic (HPLC) techniques for separating liquid-fuel type materials into saturates, aromatics, resins, and asphaltenes (SARA). The preparative method, an adaptation of a technique developed by Jewell, et. al. (1, 4), significantly decreases analysis time. The analytical technique utilizes HPLC to achieve the same separations in less time.     

Preparative argentation reversed-phase high performance liquid chromatography

In this study, a preparative chromatography method named preparative argentation reversed-phase high performance liquid chromatography (Ag-RP-HPLC) was developed by adding silver ion to the mobile phase of preparative HPLC. Firstly, an analytical Ag-RP-HPLC method was developed, and the effects of silver content and acid content in the mobile phase on the column efficiency were studied. Based on the method of linear amplification, a preparative Ag-RP-HPLC technique with optimized separation conditions was developed. The new technique was applied successfully to the separation of the unsaturated aliphatic acid amide isomers contained in Asarum forbesii Maxim. Compared with the commonly used technique of argentation normal phase chromatography, this method with little solvent consumption is simple, fast, efficient, and flexible for the isolation and purification of the unsaturated compounds.     

Purification of flavonoids and triterpene saponins from the licorice extract using preparative HPLC under RP and HILIC mode

A four‐channel preparative HPLC was employed to isolate and purify compounds from licorice extract. Two separation modes, RP and hydrophilic interaction LC (HILIC), were used in preparative HPLC. HILIC mode was adopted to resolve the purification of the compounds with similar hydrophobicity, which were co‐eluted under RP mode. Using the two separation modes during the purification process, fifteen compounds were isolated from licorice extract. The results indicated that preparative HPLC performed under HILIC mode is an efficient method for the isolation and purification of compounds from natural products.     

Application of an efficient strategy based on liquid–liquid extraction,high‐speed counter‐current chromatography,and preparative HPLC for the rapid enrichment,separation, and purification of four anthraquinones from Rheum tanguticum

This study presents an efficient strategy based on liquid–liquid extraction, high‐speed counter‐current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum. A new solvent system composed of petroleum ether/ethyl acetate/water (4:2:1, v/v/v) was developed for the liquid–liquid extraction of the crude extract from R. tanguticum. As a result, emodin, aloe‐emodin, physcion, and chrysophanol were greatly enriched in the organic layer. In addition, an efficient method was successfully established to separate and purify the above anthraquinones by high‐speed counter‐current chromatography and preparative HPLC. This study supplies a new alternative method for the rapid enrichment, separation, and purification of emodin, aloe‐emodin, physcione, and chrysophanol.     

工业制备高效液相色谱法制备淫羊藿中的黄酮系列对照品

淫羊藿甙和朝藿定A、B、C是淫羊藿中重要的活性成分,本研究应用工业制备高效液相色谱从淫羊藿粗提物中分离制备了这4个成分。淫羊藿粗提物经大孔吸附树脂粗分离获得相应的组分后,利用工业制备高效液相色谱完成精制纯化。采用自装填Chromatorex C18制备柱(220 mm×77 mm, 10 μm),乙腈-水(26:74或30:70, v/v)为流动相进行洗脱,在35 min内,实现了这4种成分的基线分离及规模制备。从300 g粗提物(总黄酮含量约20%)中获得淫羊藿甙33 g、朝藿定C 4.6 g、朝藿定B 3.7 g和朝藿定A 0.6 g,产品纯度均达到98%以上。此方法通过两步分离即可实现这4种成分的完全分离,具有快速高效、产品纯度高的特点,适于淫羊藿中淫羊藿甙、朝藿定A、B、C系列对照品的规模制备。     

反相高效液相色谱法制备洋川芎内酯Ⅰ

建立了一种快速、高效制备洋川芎内酯Ⅰ的工艺路线。以醋酸铵为改性剂,利用台阶梯度洗脱和MCI树脂柱脱盐的方式,通过反相高效液相色谱法制备,从川芎的95%(体积分数)乙醇提取物中快速分离到目标产物洋川芎内酯Ⅰ和副产物阿魏酸。经检测,二者的纯度均达到98%以上。该方法操作简便,能够排除由样品中阿魏酸所引起的峰交叉干扰,上样量大,适合于洋川芎内酯Ⅰ的大量制备。     

Isolation and characterization of thiosalicylic acid selenotrisulfide

Thiosalicylic acid selenotrisulfide(SeT) was prepared by the reaction of thiosalicylic acid and selenious acid in methanol. The precipitated SeT was partially purified by an extensive washing with methanol and pure SeT was isolated by preparative high-performance liquid chromatography (HPLC) using a reverse phase column. The HPLC method was useful both in the analysis and the isolation of SeT.     

修正高斯模型在制备液相色谱收集区间优化中的应用

近年来制备液相色谱得到了越来越广泛的应用。制备液相色谱操作条件的优化对提高其效率及节约成本非常重要。对制备高效液相色谱而言,其样品收集区间的确定及优化是其操作条件优化的重要步骤。该文以修正高斯模型(EMG模型)为理论基础,编写了一个小软件,可有效地帮助用户确定合理的样品收集区间。此软件对制备液相色谱实际应用有积极的指导及参考意义。     

反相高效液相色谱法制备纯化大豆异黄酮糖苷

利用制备高效液相色谱法从大豆总异黄酮提取物中制备出了3种大豆异黄酮糖苷。在Nova-Pak HR C18色谱柱(100 mm×25 mm i.d.,6 μm)上,以甲醇-体积分数为0.1%的乙酸水溶液(体积比为23∶77)为流动相,流速为20 mL/min,采用 等度洗脱方式,制备了3种大豆异黄酮糖苷,经质谱分析,确认它们分别为大豆苷、黄豆苷和染料木苷。高效液相色谱分析 表明,所制备的3种化合物的纯度均达到了99%以上。     

Preparative HPLC Separation of Epimeric Guaianolides

Abstract

A technique for the preparative HPLC separation of the C-4 epimeric unstable guaianolides matricin and 4-epimatricin, proazulenes isolated from Artemisia arborescens L., is reported.     

Exploiting pH mismatch in preparative high-performance liquid chromatographic recovery of ertapenem from mother liquor streams

Preparative chromatography was successfully employed to recover ertapenem from mother liquor streams. The recovery process involved concentration of mother liquor stream by evaporation, purification by reversed-phase preparative high-performance liquid chromatography (HPLC), and removal of chromatographic solvents in the recovered fractions by evaporation. HPLC feed was prepared by stripping off the organic solvents from the mother liquor using a wiped-film evaporator. Purification was first carried out on a 25 cm x 0.46 cm analytical column packed with 10-microm Kromasil C8 particles and then scaled up to a 25 cm x 5 cm preparative column. Gram-level recovery of ertapenem with high purity was achieved by exploiting a novel approach based on pH mismatch between the feed and the eluent. Purified ertapenem streams from preparative HPLC runs were combined, evaporated and recycled into the crystallizer for ertapenem isolation.     

Purification and preparation of compounds from an extract of Scutellaria barbata D. Don using preparative parallel high performance liquid chromatography

Preparative parallel high performance liquid chromatography combined with solvent partition and other pretreatments were adopted to separate and purify compounds from an extract of Scutellaria barbata D. Don. Mass-triggered fraction collection allowed the rapid and precise isolation of target compounds. Twelve compounds were isolated from the extract of S. barbata D. Don, their purity in area percent was determined by HPLC analysis, and the structures of seven compounds were further identified with HPLC/ESI-MS, (1)H NMR, and( 13)C NMR, among which 4-(3,4-dihydroxy-phenyl)-but-3-en-2-one, acacetin-7-diglucuronide, and luteolin-7-diglucuronide were the first to be identified from this plant. The results demonstrated that multi-channel parallel preparative HPLC/UV/MS is an efficient method for isolation and purification of compounds from natural products.     

Efficient purification and metabolite analysis of radiotracers using high-performance liquid chromatography and on-line solid-phase extraction

This study describes an efficient method using on-line solid-phase extraction (SPE) (Oasis HLB) for preparative HPLC purification of short-lived radiotracers for positron emission tomography (PET) and for HPLC analysis of radiotracers and their metabolites in cell homogenates, plasma and urine samples. The radiochemical purity of tracers (fluorine-18 labeled) purified using this method (Oasis column) was >99% compared to 90% when no Oasis column was used. Radiometabolites of several fluorine-18 and carbon-11-labeled tracers and one technetium-99m tracer were quantified in cell homogenates, plasma and urine samples. Samples were analyzed using Oasis column and analytical HPLC system without prior precipitation of proteins or removal of other biological matrices. The metabolites observed for the evaluated tracers were all polar relative to the unchanged tracer. The extraction repeatability was found to be good (RSD 2.2%) and recoveries of Oasis column/HPLC-injected radioactivity (plasma) were found to be high (mean recovery >91%). The same Oasis column was used for several times without back pressure build-up or decrease of the HPLC separation characteristics.     

反相液相色谱法制备纯化柠檬苦素类似物配糖体

 利用反相制备液相色谱结合吸附树脂柱色谱和离子交换色谱方法 ,从甜橙种子的提取物中纯化制备了一种柠檬苦素类似物配糖体 ,经 NMR测定为奥巴叩酮配糖体。     

Excellent combination of counter-current chromatography and preparative high-performance liquid chromatography to separate galactolipids from pumpkin

Galactolipids in the fruits of Cucurbita moschata (pumpkin) could not be completely separated by high-performance liquid chromatography (HPLC). Preparative HPLC was not available for preparing major galactolipid monomers in pumpkin. In the present paper, a combination of high-speed counter-current chromatography (HSCCC) and preparative HPLC was used for preparing the galactolipids. A fraction containing galactolipids (Fr60) from the purification of the n-butanol extract of pumpkin by macro-porous resin column chromatography was first separated by HSCCC to result in three sub-fractions of each containing two galactolipid monomers. The three sub-fractions were further separated by preparative HPLC respectively to yield six galactolipid monomers with purity more than 96%. The method is a good one for preparing galactolipid monomers from plant materials for the studies of bioactivities.     

Preparative high-performance liquid chromatographic separation of naphthodianthrones from St. John's Wort

St. John's Wort (Hypericum perforatum), a perennial flowering plant, has been used medicinally for thousands of years and has most recently been identified as an effective treatment for mild to moderate depression and neuralgic disorders. This work presents a procedure for the isolation of naphthodianthrones from St. John's Wort by an accelerated extraction and separation of marker compounds by preparative high-performance liquid chromatography (HPLC) with photodiode array detection. The accelerated extraction method minimizes the extraction time and increases the yield, and the marker compounds obtained by preparative HPLC are of 98% purity. The compounds are characterized by liquid chromatography-mass spectrometry (electrospray ionization) and NMR spectra.     

High performance liquid chromatographic evaluation of artemisinin,raw material in the synthesis of artesunate and artemether

A barrier to the development of artemisinin derivative based combination treatment of malaria is the lack of defined specifications and purity test methods for the raw material artemisinin. An HPLC method previously published in the International Pharmacopoeia to evaluate purity of artemisinin as an active pharmaceutical ingredient is adapted for use. Excellent method precision and linearity are demonstrated along with observations of robustness. In support of the development of specifications major impurities are identified using high resolution HPLC–MS, isolation via preparative HPLC followed by NMR. The identified impurities differ from those previously claimed.     

High-throughput purification of combinatorial libraries I: a high-throughput purification system using an accelerated retention window approach

We have developed a high-throughput purification system to purify combinatorial libraries at a 50-100-mg scale with a throughput of 250 samples/instrument/day. We applied an accelerated retention window method to shorten the purification time and targeted one fraction per injection to simplify data tracking, lower QC workload, and simplify the postpurification processing. First, we determined the accurate retention time and peak height for all compounds using an eight-channel parallel LC/UV/MS system, and calculated the specific preparative HPLC conditions for individual compounds. The preparative HPLC conditions include the compound-specific gradient segment for individual compounds with a fixed gradient slope and the compound-specific UV or ELSD threshold for triggering a fraction collection device. A unique solvent composition or solvent strength was programmed for each compound in the preparative HPLC in order to elute all compounds at the same target time. Considering the possible deviation of the predicted retention time, a 1-min window around the target time was set to collect peaks above a threshold based on UV or ELSD detection. Dual column preparative instruments were used to maximize throughput. We have purified more than 500 000 druglike compounds using this system in the past 3 years. We report various components of this high-throughput purification system and some of our purification results.     

用大型反相高效液相制备色谱法分离基因工程白细胞介素－2

探索了大规模生产制备基因工程白细胞介素－２（ｒＩＬ－２）的新工艺，采用等度和线性梯度相结合的方法，用大型反相高效液相制备色谱法分离提纯ｒＩＬ－２，并用电泳仪等测量了提纯物的纯度，结果表明：用新方法制备的ｒＩＬ－２纯度大于９５％，冻干后成品比活大于１０~（１０）ＩＵ／ｇ，且上样量大，在实际生产中应用价值很高。     

Development and Practical Use of a High Performance Preparative Liquid Chromatographic System

The application of an analytical high performance liquid chromatograph to preparative tasks is discussed. Large capital Investments are the nom when purchasing modern high performance liquid chromatographic equipment. In many cases an analytical HPLC system can be made to du double duty by also serving as a preparative liquid chromatograph. Often, with a small additional capital Investment and minor equipment modifications a more versatile chromatograph is obtained. This paper will briefly review the process required to convert an analytical liquid chromatograph into a preparative liquid chromatograph. The resulting unit is fully automated and is capable of continuous unattended operation for periods of up to several weeks. Finally, the use of this system is illustrated by showing the scale up of a separation from an analytical to a preparative mode resulting in the isolation of high-purity standard materials.