紫草油有效成分的高效液相色谱测定法及其在超临界流体萃取制备紫草油中的应用

紫草提取制备成的紫草油能够预防及治疗婴儿尿布疹、皮肤溃烂、湿疹等多种皮肤疾患,临床应用非常广泛,超临界流体萃取是紫草有效成分提取的优选方法.该文建立了紫草油有效成分的高效液相色谱(HPLC)测定方法,并以紫草油所含的有效成分含量为评价指标,采用三因素三水平正交试验法对紫草超临界流体萃取制备过程中的几个重要因素(萃取压力...     

超临界二氧化碳流体萃取中药苦参的生物总碱

超临界ＣＯ2流体萃取(ＣＯ2 ＳｕｐｅｒｃｒｉｔｉｃａｌＦｌｕｉｄＥｘｔｒａｃｔｉｏｎ,ＳＦＥ ＣＯ2)技术是一种新型分离提取技术,其选择分离效果好,提取率高,产物没有有机溶剂残留,有利于热敏性物质和易氧化物质的萃取[1]。苦参为豆科植物,是传统的清热燥湿类中药,其有效成分主要为生物碱。苦参生物碱具有抗肿瘤、平喘、升白、抗菌、抗病毒、抗原虫等多种功能[2]。由于生物碱在植物中多数以盐的形式存在,若直接用极性较弱的溶剂提取往往提取不完全,故在提取前需碱化,使之成为游离碱[3]。本实验用氨水作碱化剂,选用无水甲醇为夹带剂,…     

超临界流体萃取-硅胶柱收集联用提取蓬莪术中有效成分

采用超临界流体CO2萃取和硅胶柱收集在线联用,提取蓬莪术中的挥发油,随后分别用正己烷、乙醇和乙醚对硅胶柱进行选择性洗脱,从而使蓬莪术挥发油中有效成分莪术二酮的相对含量由原来单一萃取的10．7％提高到34．7％。     

天津药企超临界萃取成重大高新技术产业化项目

天津市中新药业集团第六中药厂承担的“超临界萃取技术在现代中药生产中的应用产业示范项目”,在被列为国家重点扶持的医药类高新技术产业化项目并获得国家专项资金资助基础上,通过产业化生产研发深加工,日前该项目又顺利通过本市有关部门的技术认定,认为此项目对中药现代化发展有较强的示范和带动作用,并参照国家相关办法,对该项目授予“天津市重大高新技术产业化项目”牌匾。超临界萃取技术是近年来发展起来的绿色化工技术,它是一种高效洁净的提取工艺,被广泛应用于食品保健、化工煤炭、植物提取和分离工艺中。超临界萃取技术的研究已被许多国家列为21世纪的重点发展项目。专家介绍,目前,我国采用的超临界技术对中药进行提取分离的研究多数仍停留在实验室阶段,将实验室成果引进到产业化生产中并生产出天然植物药品,对推动中药现代化进程具有重大意义。(仪器信息网)天津药企超临界萃取成重大高新技术产业化项目     

超临界流体萃取技术在中草药有效成份提取中的应用

本文介绍了超临界流体萃取技术的基本原理、优越性以及中草药有效成分提取中的应用。     

超临界流体萃取和气相色谱—质谱联用测定薄荷中有效成份

介绍用超临界流体萃取和气相色谱－质谱联用（ＳＦＥ／ＧＣ－ＭＳ）法提取和测定薄荷中的有效成分，ＳＦＥ的试验条件为：Ｄ：８－２６ＭＰａ，温度：３５－６５℃，改性剂？：１％－１０％乙醇，结果表明，在２３ＭＰａ，５５℃和７％极性剂条件下撮效率最佳，在此条件下其主成分薄荷醇的提取量为０．１６％（Ｗ／Ｗ），比水蒸气蒸馏法提取量约高３倍，比有机溶剂法提取量约高０．６倍。     

加速溶剂萃取-在线衍生-气相色谱-质谱法同时分析土壤中有机氯农药和酸性除草剂

建立了土壤中13种极性除草剂与20种非极性有机氯农药的同时萃取检测的方法.利用加速溶剂萃取过程中的温度环境与溶剂环境,使强极性氯代酸性除草剂与五氟苄基溴在萃取池内反应,酯化产物的极性显著降低.利用丙酮溶剂使之与非极性的有机氯农药同时萃取;利用衍生产物与有机氯农药的高电负性使除草剂与有机氯农药在气相色谱负化学源质谱上同时...     

人参中稀有皂苷临界二氧化碳超提取

针对人参稀有皂苷极性较小的特点,选择超临界二氧化碳流体(SFE-CO2)技术进行提取,最佳提取实验条件为:压力35 MPa,温度50 ℃,夹带剂为70%乙醇,夹带剂用量为1.7 mL/g。 利用高效液相色谱 电喷雾质谱联用分析方法分析其萃取产物,证明该提取方法的提取效率与超声提取接近,且该方法具有环境友好的特点。     

用超临界CO2萃取香草兰香料

香草兰是一种多年生藤本热带香料植物 ,有“食品香料之王”的美称 ,经济价值很高 ,要靠进口满足国内需求[1 ] 。在水果制品中添入香草兰 ,可使果香味增浓 ,但不增加热量[2 ] ;香草兰还用于化妆品业、烟草业和药品业等[3] 。它是由提取香草兰豆荚制备的。传统方法是用有机溶剂萃取 ,成本高、费时、溶剂会残留。近 2 0年才发展起来的超临界流体萃取 (Ｓｕｐｅｒｃｒｉｔｉｃａｌｆｌｕｉｄｅｘｔｒａｃｔｉｏｎ ,简称ＳＣＦＥ)技术 ,在天然产物提取以及食品工业的应用方面取得较好效果[4] 。本文用超临界ＣＯ2萃取香草兰香料 ,研究了压力、温…     

人参中稀有皂苷超临界二氧化碳提取

针对人参稀有皂苷极性较小的特点,选择超临界二氧化碳流体(SFE-CO2)技术进行提取,最佳提取实验条件为:压力35MPa,温度50℃,夹带剂为70%乙醇,夹带剂用量为1.7mL/g。利用高效液相色谱-电喷雾质谱联用分析方法分析其萃取产物,证明该提取方法的提取效率与超声提取接近,且该方法具有环境友好的特点。     

并行捕集柱SFE-HPLC在线联用系统的构建及应用

在前期研究的基础上, 发展了采用自动十通阀/并行捕集柱接口构建了SFE和HPLC在线联用的新装置, 并利用该系统对灵芝子实体的超临界萃取过程进行实时监测.     

Supercritical fluid extraction of nylon 6,6 oligomers and their characterization via liquid chromatography coupled with mass spectrometry.

This research extends previous studies regarding the application of supercritical fluid extraction (SFE) for the analysis of oligomers from nylon 6,6 fibers. The effects of CO2 pressure, extraction temperature, CO2-modifier percentage, static extraction time and dynamic extraction time on the SFE efficiency of nylon 6,6 oligomers were examined. Results from the SFE methods for oligomer extractions were compared to results from conventional solvent extraction. The extracted oligomers were identified by high-performance liquid chromatography (HPLC) with coupled on-line atmospheric pressure chemical ionization mass spectrometry and HPLC fractionation coupled with off-line liquid secondary ion mass spectrometry.     

Rhodium and palladium β-diketonate determination with on-line supercritical fluid extraction-high performance liquid chromatography via solid phase extraction

 An on-line system of supercritical fluid extraction (SFE) and high performance liquid chromatography (HPLC) via solid phase extraction (SPE) is described for the determination of palladium and rhodium 2,2,6,6-tetramethyl-3,5-heptanedione-(thd) as well as rhodium-acetylacetonate-(acac) and benzylacetonate-(bzac) chelates. The chelates were extracted with supercritical CO₂ from sand and humic acid, concentrated on SPE cartridges and analysed with HPLC. Two cartridge materials were tested and compared to off-line trapping. The percentage of the breakthrough and cartridge retained material were measured in liquid dichloromethane. The SFE conditions could be optimized to separate metal chelates during the extraction. The supercritical fluid (SF) behaviour of different ligands on rhodium were investigated. Received: 19 July 1996/Revised: 11 December 1996/Accepted: 14 December 1996     

超临界流体萃取与其它分析技术的联用

用超临界流体萑取进行分析样品处理，有快速，高效，低消耗，污染少等优点。本文对ＳＦＥ的原理，特点，与其它技术的联用及其在分析化学诸领域的应用作了综述，其中重点介绍了ＳＦＥ与色谱技术的在线联用，内容包括接口等。     

The use of nitrous oxide for supercritical fluid extraction of pharmaceutical compounds from animal feed

Supercritical fluid extraction (SFE) coupled “off-line” with HPLC analysis has been applied to pharmaceutical analysis: two different matrixes (rodent and dog feed) were spiked with compounds under investigation in pharmacological studies in order to study the supercritical extraction of such matrixes prior to further analysis and quantification of the compounds of interest. The fluid flow-rate in the SFE system was governed by the geometric characteristics (internal diameter and length) of the linear fused silica capillaries. The changes in fluid flow-rate, between experiments, for each new restrictor, required the introduction of the term Total Gaseous Fluid Volume (TGFV), which enabled a series of extraction results to be compared. The comparative behavior of nitrous oxide and carbon dioxide as supercritical extraction fluids was investigated. Results obtained using pure supercritical fluids with high solvating power (density 0.79 g ml^?1) and fluids modified with a polar liquid solvent (methanol and acetonitrile) are discussed.     

Fat content for nutritional labeling by supercritical fluid extraction and an on-line lipase catalyzed reaction

A method using sequential supercritical fluid extraction (SFE) and enzymatic transesterification has been developed for the rapid determination of total nutritional fat content in meat samples. SFE conditions of 12.16 MPa and 50°C were utilized to extract lipid species from the sample matrix. The enzymatic transesterification of the lipids by methanol was catalyzed by an immobilized lipase isolated from Candida antarctica. Conversion of the triglycerides to fatty acid methyl esters was monitored by supercritical fluid chromatography, while the fatty acid content of the extract was determined by capillary gas chromatography (GC). Total fat, saturated fat and monounsaturated fat contents were calculated from the GC data and compared to values from traditional extraction and lipid determination methods. Both off-line SFE and automated SFE followed by on-line GC analysis using two different instruments were utilized in this study. The enzymatic-based SFE method gave comparable results to the organic solvent extraction-based method followed by conventional BF₃-catalyzed esterification.     

Supercritical fluid extraction in plant essential and volatile oil analysis

The use of supercritical fluids, especially carbon dioxide, in the extraction of plant volatile components has increased during two last decades due to the expected advantages of the supercritical extraction process. Supercritical fluid extraction (SFE) is a rapid, selective and convenient method for sample preparation prior to the analysis of compounds in the volatile product of plant matrices. Also, SFE is a simple, inexpensive, fast, effective and virtually solvent-free sample pretreatment technique. This review provides a detailed and updated discussion of the developments, modes and applications of SFE in the isolation of essential oils from plant matrices. SFE is usually performed with pure or modified carbon dioxide, which facilitates off-line collection of extracts and on-line coupling with other analytical methods such as gas, liquid and supercritical fluid chromatography. In this review, we showed that a number of factors influence extraction yields, these being solubility of the solute in the fluid, diffusion through the matrix and collection process. Finally, SFE has been compared with conventional extraction methods in terms of selectivity, rapidity, cleanliness and possibility of manipulating the composition of the extract.     

Routine determination of benzo[a]pyrene at part-per-billion in complex industrial matrices by multidimensional liquid chromatography

A rapid and selective high performance liquid chromatography (HPLC) method using a column-switching technique has been developed for the determination of benzo[a]pyrene in complex mixtures containing polycyclic aromatic hydrocarbons. The diluted sample is directly injected into the chromatographic system without pre-treatment. The purification is performed on-line using three cleaning columns filled with various stationary phases. The sample preparation, a simple dilution, and the analysis time do not exceed 45 min. The method developed was used to analyze industrial products such as oil, bitumen, etc. and was compared with an off-line method requiring treatment and extraction steps before the analysis.     

Comparison of methods for quantitative analysis of additives in low-density polyethylene using supercritical fluid and enhanced solvent extraction.

On-line supercritical fluid extraction-supercritical fluid chromatography (SFE-SFC) with cryogenic trapping was used to extract and separate five additives from a low-density polyethylene (LDPE) sample. A glass tube filled with glass wool afforded excellent collection efficiency for the extracted analytes. Additive spiked sand was employed to optimize the various parameters of the on-line SFE-SFC system. Calibration curves from the spiked sand studies for on-line SFE-SFC were obtained with good linearities for quantitation. Results obtained on additives in LDPE from on-line SFE-SFC were comparable to those from off-line SFE-HPLC and off-line enhanced solvent extraction (ESE)-HPLC for all additives except Irganox 1076. However, the precision obtained with on-line SFE-SFC was lower than that from off-line SFE-HPLC and off-line ESE-HPLC due to the small sample size employed in the on-line system. Considerable clean-up of the ESE extract was required prior to chromatographic analysis. On-line SFE-SFC minimized the sample handling and eliminated the use of organic solvent. Despite the lower than expected precision, the on-line SFE-SFC method for quantitation of polymer additives appears to be reliable and robust for application in routine quality control analysis.     

An SPE column-teflon sleeve assembly for in-line retention during supercritical fluid extraction of analytes from biological matrices

An in-line collector assembly designed for use in supercritical fluid extraction (SFE) vessels is described. This assembly enables solutes extracted by supercritical fluids (SF) to be retained in-line on standard solid phase extraction (SPE) columns. The assembly consists of a standard 1 mL or 3 mL SPE column fitted into a specially fabricated Teflon© sleeve. The SPE column-Teflon sleeve assembly is inserted into the SFE vessel followed by the sample matrix. This unit forms a leak-tight seal with the vessel's end-cap up to pressures of 680 bar. The choice of sorbents used in the in-line SPE columns is dependent upon the properties of the solute in the supercritical state. After SFE is completed, the SPE column is removed and the solutes are recovered in 1–2 mL of the eluting solvent. No further clean-up is normally required prior to chromatographic analysis of the analyte. A comparison was made of recoveries by in-line and off-line (after SF decompression) techniques for the SFE of three anabolic steroids in fortified chicken liver. The HPLC chromatograms of the steroids from the off-line SPE columns were too complex for quantitation, because of coeluting artifacts, whereas chromatograms obtained from in-line SPE columns were free from UV-absorbing interferences and were easily quantified.