Determination of polycyclic aromatic hydrocarbons with supercritical fluid extraction and chromatography（SFE／SFC）

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Influence of Modifiers on Supercritical Fluid Chromatography (SFC) and Supercritical Fluid Extraction (SFE), Part I

It is important to understand the mechanism and implications of different modifiers on analytical and preparative processes under chromatography with supercritical fluids (SFs) and under extraction with SFs. Supercritical fluid chromatography (SFC) and supercritical fluid extraction are generally carried out with neat supercritical carbon dioxide (SCCO2) or with SCCO2 containing modifiers (or cosolvents), especially for strongly polar compounds. For example, methanol is added as a cosolvent/modifier to SCCO2 for the extraction/separation of polar compounds. This paper discusses the influence of the modifier on the colligative properties of the principal mobile phase, which may define the situation in the total mobile phase in a chromatography column or in parts of a column under SFC. No colligative behavior of solutions reflects individual properties of the solutes. Their cross-interactions with solvents are discussed.

Simultaneous determination of amino acids in different teas using supercritical fluid chromatography coupled with single quadrupole mass spectrometry

Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) was developed to simultaneously determine 11 amino acids in different types of tea (green teas, Oolong tea, black tea and Pu-erh tea). The separation conditions for the analysis of the selected amino acids including the column type, temperature and backpressure as well as the type of additive, were carefully optimized. The best separation of the 11 amino acids was obtained by adding water (5%, v/v) and trifluoroacetic acid (0.4%, v/v) to the organic modifier (methanol). Finally, the developed SFC-MS method was fully validated and successfully applied to the determination of these amino acids in six different tea samples. Good linearity (r ≥ 0.993), precision (RSDs≤ 2.99%), accuracy (91.95%-107.09%) as well as good sample stability were observed. The limits of detection ranged from 1.42 to 14.69 ng/mL, while the limits of quantification were between 4.53 and 47.0 ng/mL. The results indicate that the contents of the 11 amino acids in the six different tea samples are greatly influenced by the degree of fermentation. The proposed SFC-MS method shows a great potential for further investigation of tea varieties.

Advances of supercritical fluid chromatography in lipid profiling

Supercritical fluid chromatography(SFC) meets with great favor due to its high efficiency, low organic solvent consumption, and the specialty for the identification of the isomeric species. This review describes the advances of SFC in targeted and untargeted lipid profiling. The advancement of the SFC instruments and the stationary phases are summarized. Typical applications of SFC to the targeted and untargeted lipid profiling are discussed in detail. Moreover, the perspectives of SFC in the lipid profiling are also proposed. As a useful and promising tool for investigating lipids in vitro and in vivo, SFC will predictably obtain further development.

Separation of Enantiomers of Clopidogrel on Chiral Stationary Phases by Packed Column Supercritical Fluid Chromatography

A packed column supercritical fluid chromatography (SFC) method for the separation of clopidogrel enantiomers on a chiral stationary phase and CO2 with modifier as mobile phase has been developed at an analytical scale. Among 11 different 2 stationary phases the Chiral cel OD-H column showed by far the best separation properties. The influence of different modifiers, injection solvents, temperature, and pressure, and density of the fluid, respectively, on the separation behaviour has been studied. It was found that the separation behaviour strongly depends on the type of modifier and the modifier content. Temperature and pressure are of less influence.

Review: Isomer Separation, Chiral Resolution, and Structure Elucidation Analyses Are the Future of Analytical Supercritical Fluid Chromatography—Mass Spectrometry

In 1822, almost 200 years ago, Baron Charles Cagniard de Latour (1777-1859) discovered the critical phenomena or critical state [1] [2]. At that time, it was described as a curiosity. However, it is now used as an advanced extraction and analytical technology in industry and research. Extraction with supercritical fluids (SFs) was welcome from the very beginning. In the present paper, the application to chromatography of the critical phenomena of compressed gases or overheated liquids as supercritical fluids will be discussed. Supercritical Fluid Chromatography (SFC) received an uneasy welcome, mainly because of the lack of commercially available analytical instruments. Even today, only a small number of industrial companies are manufacturing SFC instrumentation. A very small spectrum of columns is manufactured specially for SFC. SFC is not accepted by Pharmacopeia committees for the analysis of drugs and medical forms to the same extent as Gas Chromatography, High-Performance Liquid Chromatography or even Thin Layer Chromatography. The present status and future perspectives for SFC will be discussed.

Fast analysis of derivatives of polycyclic aromatic hydrocarbons in soil by ultra-high performance supercritical fluid chromatography after supercritical fluid extraction enrichment

An efficient and environment-friendly method for simultaneous determination of 13 typical derivatives of polycyclic aromatic hydrocarbon(PAH)in petroleum-polluted soil with nitro-,oxy-and alkylfunctional group was developed using supercritical fluid extraction(SFE)followed by ultra-high performance supercritical fluid chromatography(UHPSFC).Parameters of UHPSFC,including type of stationary phase and mobile phase modifiers,gradient elution process,backpressure,column temperature,and the flow rate of mobile phase,were systematically optimized,achieving a fast separation within4.2 min.Limits of detection(LOD)were 0.005-0.1μg mL^(-1)or 0.1-2.0 ng g^(-1),respectively,with a good repeatability(RSD<5.0%).Before UHPSFC-PDA analysis,the PAH-derivatives in soil samples were effectively enriched in 15.0 min using SFE with an online carbon nanotubes(CNTs)collection trap.The soil samples were analyzed by the proposed method and the results were verified by GC-MS.Thus,SFE equipped with an online CNTs trap followed by UHPSFC-PDA analysis,which only consumed about2.0 mL organic solvent for a whole run,has been demonstrated to be an efficient way for screening and quantitative analysis of trace-level PAH-derivatives in soil samples.

Packed Supercritical Fluid Chromatography for the Analyses and Preparative Separations of Palm Oil Minor Components

This paper depicts a brief review on the applications of packed supercritical fluid chromatography (SFC) in palm oil analyses and purifications from early 1990s to date. Packed SFC has been used for the analyses of various palm oil components. The analytical separations have also been scaled up to preparative scale that leads to the recovery of high value components from palm oil. This review encompasses both analytical and preparative SFC in the oil palm processing.

Chiral Separation of Ibuprofen by Supercritical Fluid Chromatography

用为 enantioselective 化合物的准备的 chiral 固定相(CSP ) 的分离方法广泛地被使用。在这个工作，超级批评液体层析(SFC ) 被建议解决 chiral 混合物。在压力，温度和国际语音学协会的内容与变化为外消旋的布洛芬，保留因素和决定的 thechiral 分离决定最佳操作条件(%，由体积)在超级批评 CO_2 ， wereinvestigated.Experiments 证明保留因素随温度的压力和减少的增加减少了。保留因素被国际语音学协会的内容也在流动相影响，作为在增加的超级批评液体的国际语音学协会的内容， enantiomers 的保留因素 decreased.Theresolution 随优化试验性的条件的 supercriticalfluid.Through 的国际语音学协会的增加变得更坏，有 13MPa,311.15 K 和4% IPAin CO_2 的一个 SFC 过程被获得。当与常规 liquidchromatography.This 获得的不对称的峰形相比工作证明发达超级批评液体层析过程对布洛芬 enantiomers 的 chiral 分离合适时， enantiomers 的峰形与超级批评液体层析是对称的。

THEORY FOR STEP AND PULSE METHOD OF SUPERCRITICAL FLUID CHROMATOGRAPHY

1 INTRODUCTIONSupercritical fluid chromatography(SFC),employing supercritical fluid as mobilephase,originated in the 1960’s [1-4].Since 1980’s extensive research work has beenperformed on SFC,chiefly for analytical purposes [5,6].SFC was then adopted for thedetermination of thermodynamic properties such as partial molar volume,and partialmolar enthalpy of solutes in both mobile phase and stationary phase and the solutedistribution coefficient between two phases [7- 11].Partial molar properties can be de-

Simultaneous enantioseparation and simulation studies of atenolol,metoprolol and propranolol on Chiralpak^■IG column using supercritical fluid chromatography

Enantioseparation of threeβ-blockers,i.e.,atenolol,metoprolol and propranolol,was studied on amylose tris(3-chloro-5-methylphenylcarbamate)immobilized chiral stationary phase using supercritical fluid chromatography(SFC).The effect of organic modifiers(methanol,isopropanol and their mixture),column temperature and back pressure on chiral separation ofβ-blockers was evaluated.Optimum chromatographic separation with respect to resolution,retention,and analysis time was achieved using a mixture of CO_(2) and 0.1%isopropyl amine in isopropanol:methanol(50:50,V/V),in 75:25(V/V)ratio.Under the optimized conditions,the resolution factors(Rs)and separation factors(a)were greater than3.0 and 1.5,respectively.Further,with increase in temperature(25-45℃)and pressure(100-150 bars)there was corresponding decrease in retention factors(k),a and Rs.However,a reverse trend(a and Rs)was observed for atenolol with increase in temperature.The thermodynamic data from van’t Hoff plots revealed that the enantioseparation was enthalpy driven for metoprolol and propranolol while entropy driven for atenolol.To understand the mechanism of chiral recognition and the elution behavior of the enantiomers,molecular docking studies were performed.The binding energies obtained from simulation studies were in good agreement with the elution order found experimentally and also with the free energy values.The method was validated in the concentration range of 0.5-10μg/m L for all the enantiomers.The limit of detection and limit of quantitation ranged from 0.126 to 0.137μg/m L and 0.376-0.414μg/m L,respectively.The method was used successfully to analyze these drugs in pharmaceutical preparations.

Overview of the Analytical Lifecycle of Supercritical Fluid Chromatography Methods

In recent times, the overall interest over Supercritical Fluid Chromatography (SFC) is truly growing within various domains but especially for pharmaceutical analysis. However, in the best of our knowledge modern SFC is not yet applied for drug quality control in the daily routine framework. Among the numerous reported SFC methods, none of them could be found to fully satisfy to all steps of the analytical method lifecycle. Thereby, the present contribution aims to provide an overview of the current and past achievements related to SFC techniques, with a targeted attention to this lifecycle and its successive steps. The included discussions were therefore structured accordingly and emphasizing the analytical method lifecycle in accord with the International Conference on Harmonisation (ICH). Recent and important scientific outputs in the field of analytical SFC, as well as instrumental evolution, qualification strategies, method development methodologies and discussions on the topic of method validation are reviewed.

Rapid Separation of Five Cyclosporin Analogs by Supercritical Fluid Chromatography

Recently there has been a resurgence of interest in cyclic peptides due to their therapeutic advantages in terms of potency, permeability, proteolytic stability, and unique selectivity relative to traditional smaller drug molecules. Cyclosporin is a family of cyclic peptides widely used as autoimmune suppression agents. Cyclosporin analogs consist of eleven amino acids with the main difference lying at the side chain of its amino acid residues. In this study, a single step separation method was developed utilizing Supercritical Fluid Chromatography (SFC) to resolve five naturally occurring cyclosporin analogs (Cyclosporin A, B, C, D, and H) on a bare silica-packed column. The optimized method involved use of ethanol-modified carbon dioxide as mobile phase on a bare silica column at 80 °C and UV detection at 220 nm. Although column temperature and back pressure generally had insignificant effect on SFC separation, it was found in our study that increasing temperature and pressure greatly improved peak shape and resolution.

Influence of Modifiers, Extractants, and Trappers on Lipid Composition with Liquids in Standard State Extraction, Supercritical Fluid Extraction and Trapping by Supercritical Fluid Extraction, Part II

Modifiers have a broad array of influences on extraction with liquids in standard state, supercritical fluid extraction (SFE), trapping by SFE and supercritical fluid chromatography (SFC). They can significantly change the qualitative and quantitative results. Quantitative and qualitative results can be influenced by different extractants and modifiers in different ways as it was shown by Brondz et al. at 2007 in “The real nature of the indole alkaloids in Cortinarius infractus: Evaluation of artifact formation through solvent extraction method development”, J. Chromatography A, 1148, 1-7. The choice of correct extractant, modifier, and trapper to the bulk mobile phase for supercritical fluids (SFs) or for liquids in subcritical or in the liquids in standard state is a challenge in any extraction procedure. This is the second paper in a sequence that describes the influence of extractants and modifiers on the performance of SFs and results of extraction with liquids in standard state and SFE. Here, attention is given to possible mistakes in qualitative and quantitative results by poor understanding of the influence of extractants, modifiers, and trappers on extraction and trapping process by a careless choice of extractant, modifier, and trapper for extraction with liquids in standard state and SFE. The SF chosen for discussion in the paper is CO2. However, similar effects can be observed with use of other SFs and fluids in subcritical and standard states. In this paper, the discussion of lipids, fatty and carboxylic acids have been chosen as target analytes for extraction, trapping and analysis. Some examples from extraction with liquids in the standard state and trapping in the supercritical state (collection) have been furnished with the wrong extractant, modifier, or trapper which is presented for illustration of inappropriate choice of extractants, modifiers, and trappers.

烟草中甲霜灵的手性分离方法差异研究

对比反相液相色谱-串联质谱(RPLC-MS/MS)和超临界流体色谱-串联质谱(SFC-MS/MS)手性分离烟草中甲霜灵的差异。烟草样品经乙腈提取、盐析分层、快速滤过型净化(multi-Plug Filtration Cleanup,m-PFC)柱净化后,分别采用RPLC-MS/MS和SFC-MS/MS进行手性分离。从多个性能参数(分离效率、线性、选择性、回收率、重复性、灵敏度、基质效应等)对两种方法进行了全面比较。采用不同的分离方法,在10~500 ng/mL范围内,甲霜灵的不同异构体均可呈现良好的线性关系(R^(2)≥0.9993)。在各异构体加标浓度为0.1、0.5、2.0 mg/kg水平下,采用不同的分离方法均可获得满意的回收率(88.7%~96.2%)和良好的重复性(RSD<7.0%)。结果表明:RPLC-MS/MS和SFC-MS/MS具有互补性,均适用于手性分离和测定烟草基质中的甲霜灵。

超临界萃取结合分子蒸馏纯化生姜精油及其挥发性成分分析

为研究超临界萃取结合分子蒸馏纯化生姜精油的最佳工艺参数,鉴定生姜精油的挥发性成分,以舒城黄姜为原料,通过单因素试验和正交试验优化了超临界CO_(2)流体萃取(supercritical CO_(2)fluid extraction,SFE)生姜油的最佳工艺条件,考察了分子蒸馏(molecular distillation,MD)温度对分离纯化生姜精油效果的影响,并通过气相色谱-质谱联用对生姜精油的挥发性成分进行了分析。结果表明,超临界CO_(2)流体萃取结合分子蒸馏(SFE-MD)纯化生姜精油的最佳工艺条件为萃取压力24 MPa、萃取温度45℃、萃取时间2 h、分子蒸馏温度80℃,在此条件下,生姜精油的综合得率为2.53%,显著高于水蒸气蒸馏精油得率0.96%(P<0.05)。挥发性成分分析显示,α-姜烯、β-倍半水芹烯、β-红没药烯是生姜精油的主要挥发性成分,百分含量达70%以上,其中α-姜烯百分含量为42.13%,高于水蒸气蒸馏生姜精油α-姜烯百分含量40.59%。该方法绿色环保,萃取率高,精油品质好,为生姜精油的进一步研究开发提供参考。

超临界流体-蒸发光散射法测定常见油脂类药用辅料皂化后的脂肪酸组成及其在油脂鉴别中的应用

脂肪酸是油脂类药用辅料的重要组成成分,可直接反映油脂类药用辅料及制剂的质量和安全性。本研究利用超临界流体色谱-蒸发光散射检测器,建立了同时测定肉豆蔻酸、棕榈酸、硬脂酸、花生酸、二十二烷酸和木蜡酸6种脂肪酸的分析方法。为避免脂肪酸与酯相互转化而造成的脂肪酸种类与含量测定偏差,本方法采取先皂化后测定的方式,并系统优化了实验条件,实现了6种脂肪酸的定量分析。在优化的实验条件下,6种脂肪酸可在12 min内实现高效分离,并且在各自的质量浓度范围内线性关系良好,检出限和定量限分别为5~10 mg/L和10~25 mg/L,加标回收率为80.93%~111.66%。本文所建立方法灵敏,高效,重复性和稳定性好,满足油脂类药用辅料中脂肪酸的分析要求,并成功应用于5种常见油脂类药用辅料(玉米油、大豆油、椰子油、橄榄油、花生油)中6种脂肪酸的含量测定;同时结合主成分分析方法,实现了对不同油脂类药用辅料的准确判别,为油脂类药用辅料的快速鉴别和掺伪分析提供了有价值的参考。

在线毛细管柱SFC/FTIR联用方法

建立了一种以CO_2为流动相的毛细管柱SFC/FTIR联用方法,实现了对多环芳烃混合物和催眠药混合物的分离。其在线红外光谱图具有高信噪比,可直接用于混合物组分定性分析。该法对甲基丙烯酸甲酯的v_(c—o)带和对萘的v_(c—c)带的检测限分别为25ng和102ng。

茄尼醇的SFC制备色谱分离工艺

采用ZORBAX SB-C18(250 mm×9.4 mm I.D.,5μm)色谱柱为固定相,SC-CO2/甲醇为流动相,考察了超临界流体色谱分离提纯烟草萃取物中茄尼醇的工艺条件、流动相流速和改性剂含量对分离度的影响,以及温度和压力对茄尼醇容量因子、茄尼醇与相邻色谱峰组分分离度和选择性因子的影响。通过采用选定SFC分离工艺条件,茄尼醇产品纯度达到94.9%。

SFC和GC/MS快速测定茶叶中咖啡因(英文)

采用超临界流体色谱和气-质联用分别测定茶叶中咖啡因,结果表明:(1)用CO2作流动相,加5%的CH3OH做改性剂,SFC所得结果令人满意,3min完成分析。(2)气-质联用测定7min完成。两个方法都可用于茶叶中咖啡因的快速分析,茶叶中共存的其它组分不干扰测定。