超临界流体色谱在金属络合物和金属有机化合物中的分析应用

超临界流体色谱（SFC）在色谱分离过程中能在较低的温度下分析对热不稳定性的化合物,包括金属络合物和金属有机化合物。本文总结了近来文献报道的各种过渡金属、重金属、镧系和锕系以及铅、汞和锡的金属有机化合物的SFC分离,还讨论了SFC检测系统和金属有机化合物的溶解度的测定。     

Analysis of turkish lignite tar by coupled LC/GC,GC/MS,and capillary SFC

This work describes the analysis of a pyrolysis product of a lignite sample obtained from the Turkish Goynuk reserve. The aliphatic, aromatic and polar compounds present in the tar are separated and identified by various chromatographic techniques: Capillary gas chromatography/mass spectrometry (GC/MS), on-line high performance microbore liquid chromatography/capillary gas chromatography (LC/GC) and capillary supercritical fluid chromatography (SFC). The suitability of each technique for this particular application is discussed, and semi-quantitative results are presented for the major components detected.     

Supercritical fluid chromatography-mass spectrometry for chemical analysis

Chromatography with a supercritical fluid as the mobile phase was suggested more than four decades ago (Klesper, E., Corwin, A. H., Turner, D. A., J. Org. Chem. 1962, 27, 700-701). Supercritical fluid chromatography (SFC) is basically a hybrid of GC and LC that eases the resolution of a mixture of compounds not conveniently resolved by either GC or LC. The mobile phases for SFC have low viscosities and high diffusion coefficients compared to those for HPLC and allow for high efficiency separations. SFC uses supercritical fluid as the mobile phase, polar organic solvents as the modifiers in conjunction with acidic/basic compounds as additives to run the chromatographic process like in HPLC. In many applications, SFC-based methods are advantageous over HPLC-based methods as a separation tool in terms of efficiency and economical impact perspectives. Today, the availability of commercial hardware and API interfaces with a mass spectrometer makes SFC even more widely applicable for chemical analysis in many research fields. This review summarizes a variety of novel SFC-MS methods for chemical analysis that have been reported in the peer-reviewed publications.     

Supercritical fluid chromatography—mass spectrometry coupling

Over the past five years, an increasing number of studies have been published on supercritical fluid chromatography (SFC) and combined supercritical fluid chromatography—mass spectrometry (SFC—MS), demonstrating their advantages for the separation and analysis of non-volatile or thermally labile compounds. Further technological developments are expected to make SFC (and specially SFC—MS) a puissant, routine analytical tool that is complementary to gas chromatography (GC) (and GC—MS) and liquid chromatography (LC) (and LC—MS). Because of supercritical fluid properties, SFC—MS may be more easily implemented than LC—MS and better performance may be obtained for some types of substances or when complex mixtures must be analysed.     

Determination of Microcystins in Cyanobacteria by Supercritical Fluid Extraction and Liquid Chromatography‐Tandem Mass Spectrometry

Abstract

A method for the detection of microcystins (microcystin LR, RR, and YR) in cyanobacteria by supercritical fluid extraction (SFE) and liquid chromatography‐mass spectrometry (LC/MS) has been developed. Supercritical fluids for the analytical extraction of nonvolatile, higher molecular weight compound, and microcystins from cyanobacteria were investigated. The microcystins included in this study are sparsely soluble in neat supercritical fluid CO₂. However, the microcystins was successfully extracted with a ternary mixture (90% CO₂, 9.5% methanol, 0.5% water) at 40°C and 250 atm. The polar carbon dioxide‐aqueous methanol fluid system gave high extraction efficiency for the extraction of the polar microcystins from cyanobacteria. The microcystins were determined by liquid chromatography‐tandem mass spectrometry (LC/MS/MS).     

Microwave plasma torch analytical atomic spectrometry

The microwave plasma torch (MPT), as a relative new source, has found extensive use in atomic spectrometry. In this review, the fundamental features and characteristics of the MPT are summarized and compared with other kinds of analytical atomic sources, such as the more popularly used inductively coupled plasma (ICP), the direct current plasma (DCP), as well as other kinds of microwave plasmas (MWPs). Since the MPT offers some attractive features, it has been used as an excitation source for atomic emission spectrometry (MPT-AES), including the atomic emission detection (AED) for gas chromatography (GC), liquid chromatography (LC) and supercritical fluid chromatography (SFC). Also, it has been used either as an ionization source for atomic mass spectrometry (MPT-AMS) or an atomization source for atomic fluorescence spectrometry (MPT-AFS). The historical development and recent improvements in these MPT atomic spectrometric techniques are evaluated with emphasis on the analytical advantages and limitations. In addition, the future research directions and the application prospects of MPT atomic spectrometry (MPT-AS) are discussed.     

Development of supercritical fluid chromatography coupled with mass spectrometry method for characterization of a nonionic surfactant and comparison with liquid chromatography coupled with mass spectrometry method

The supercritical fluid chromatography coupled with mass spectrometry (SFC‐MS) method and liquid chromatography coupled with mass spectrometry (LC‐MS) method were developed for the separation and characterization of poly (ethylene oxide) methyl glucose sesquistearate (PEO‐Glu‐sesquistearate). The products of PEO‐Glu‐sesquistearate are composed of complex oligomers. The relationship between molecular structure of these oligomers and chromatographic retention behavior in both SFC and LC were discussed and compared. As compared with LC, hydrophobic moieties of compounds favor the fast elution in SFC. The different series can be better separated by LC, while the homologues compounds in same series can be better separated by SFC, and SFC‐MS provided more comprehensive structural information. Different series such as PEO‐distearate, PEO‐stearate, PEO, PEO‐Glu‐tetrastearate, PEO‐Glu‐tristearate, PEO‐Glu‐distearate, PEO‐Glu‐stearate, and PEO‐Glu were identified by MS/MS.     

Supercritical Fluid Chromatography–Mass-Spectrometry of Nitrogen-Containing Compounds: Atmospheric Pressure Ionization

Journal of Analytical Chemistry - Supercritical fluid chromatography (SFC) in combination with mass spectrometry is a promising alternative to traditional chromatographic methods for the separation...     

Coupling techniques in LC/MS and SFC/MS

Summary Techniques and applications of analytical instruments combining a chromatographic technique, including liquid chromatography and supercritical fluid chromatography, with mass spectrometry (LC/MS and SFC/MS), that have appeared over the past five years, are reviewed and discussed. It is shown that still many different methods co-exist and have both specific advantages and limitations. SFC/MS appears easier to run for many compounds so far analysed by conventional LC/MS methods. On the other hand, new LC/MS methods that use fast atom bombardment or electrospray ionization have the greater potential for the investigation of polar biopolymers.     

High‐resolution GC/MS studies of a light crude oil fraction

The continuous development in analytical instrumentation has brought the newly developed Orbitrap‐based gas chromatography / mass spectrometry (GC/MS) instrument into the forefront for the analysis of complex mixtures such as crude oil. Traditional instrumentation usually requires a choice to be made between mass resolving power or an efficient chromatographic separation, which ideally enables the distinction of structural isomers that is not possible by mass spectrometry alone. Now, these features can be combined, thus enabling a deeper understanding of the constituents of volatile samples on a molecular level. Although electron ionization is the most popular ionization method employed in GC/MS analysis, the need for softer ionization methods has led to the utilization of atmospheric pressure ionization sources. The last arrival to this family is the atmospheric pressure photoionization (APPI), which was originally developed for liquid chromatography / mass spectrometry (LC/MS). With a newly developed commercial GC‐APPI interface, it is possible to extend the characterization of unknown compounds. Here, first results about the capabilities of the GC/MS instrument under high or low energy EI or APPI are reported on a volatile gas condensate. The use of different ionization energies helps matching the low abundant molecular ions to the structurally important fragment ions. A broad range of compounds from polar to medium polar were successfully detected and complementary information regarding the analyte was obtained.     

Development of a qualitative liquid chromatography/tandem mass spectrometric method for the detection of narcotics in urine relevant to doping analysis

A new screening procedure for 18 narcotics in urine for anti-doping purposes has been developed using liquid chromatography/triple quadrupole mass spectrometry (LC/MS). Electrospray ionization (ESI) was used as interface. Infusion experiments were performed for all substances to investigate their mass spectrometric behaviour in terms of selecting product specific ions. These product ions were then used to develop a tandem mass spectrometric method using selected reaction monitoring (SRM). For the LC/MS analysis, chromatography was performed on an octadecylsilane column. The total run time of the chromatographic method was 5.5 min. For the sample preparation prior to LC/MS analysis, the urine samples were liquid-liquid extracted at pH 9.5 after overnight enzymatic hydrolysis. Two extraction solvents were evaluated: dichloromethane/methanol 9/1 (v/v), which is currently used for the extraction of narcotics, and diethyl ether, used for the extraction of steroids. With diethyl ether the detection limits for all compounds ranged between 0.5 and 20 ng/mL and with the mixture containing dichloromethane the detection limits ranged between 0.5 and 10 ng/mL. Taking into account the minimum required performance limits of the World Anti-Doping Agency of 200 ng/mL for narcotics, diethyl ether can also be considered as extraction solvent for narcotics. Finally, the described method was applied to the analysis of urine samples previously found to contain narcotics by our routine gas chromatography/mass spectrometry (GC/MS) method.     

Isolation of palm tocols using supercritical fluid chromatography

Crude palm oil contains 600 to 1000 ppm of tocols in the form of tocopherols and tocotrienols. These palm tocols have been isolated and analyzed in the past by various chromatographic techniques such as open column chromatography, high-performance liquid chromatography, as well as thin-layer chromatography. Supercritical fluid chromatography (SFC) has emerged as a more advanced chromatographic technique in recent years. The tocols present in palm oil are successfully isolated using SFC. Identification of these tocols is supported by various spectroscopic techniques such as 1H NMR, 13C NMR, and mass spectrometry.     

Capillary and packed column SFC/MS

A frit restrictor interface for capillary column supercritical fluid chromatography/mass spectrometry (SFC/MS) has been constructed and used for the analysis of high boiling point alkanes. Packed column SFC/MS is described using both a moving belt liquid chromatographic/mass spectrometric interface and a thermospray source in the filament-on mode.     

超临界流体色谱法分离手性化合物的进展

超临界流体色谱（ＳＦＣ）是一种很有潜力的色谱分离技术,可以弥补高效液相色谱（ＨＰＬＣ）和气相色谱（ＧＣ）在手性对蚋物分离方面的不足。本文不但介绍了ＳＦＣ仪器的结构特点,ＳＦＣ与手性固定相（ＣＳＰｓ）结合在手性分离领域中的应用和最新进展,还对ＳＦＣ与其它色谱技术的分离效果进行了评价。文献３９篇。     

超临界流体色谱在生物工程中应用的新进展

超临界流体色谱（SFC）是高效液相色谱（HPLC）和气相色谱（GC）的重要补充技术。用SFC可以分离多数不能用GC分离的低挥发性物质。与传统的HPLC相比，SFC的分离速度更快、效率更高。本文综述了SFC在生物分子分离分析方面应用的新进展。引用文献74篇。     

Supercritical fluid chromatographic solvatochromic modifier polarity studies

To understand the chromatographic process as a whole, whether it be for gas chromatography (GC), liquid chromatography (LC), or supercritical fluid chromatography (SFC), one needs to know the chemical and physical nature of the mobile and stationary phases and also the interactions that take place between analytes (solutes) and the two phases. An approach towards Investigating the ways that stationary and mobile phases contribute to chromatographic retention Involves exploring the effects of solvent polarity on the strength of the mobile phase. In SFC this could involve determining the polarity of several different modifier/carbon dioxide mobile phases. In this paper, the use of a solvatochromic indicator to learn more about the effects of SFC modifier/mobile phase polarity will be investigated and discussed using several different modifiers and a diolmodified silica column.     

State-of-the art of selective detection and identification of I-, Br-, Cl-, and F-containing compounds in gas chromatography and liquid chromatography

This review article presents an overview of halogen-specific detection in gas chromatography (GC) and liquid chromatography (LC). Attention is primarily focused on the use of plasma emission spectroscopy and plasma mass spectrometry as detectors, but other halogen-selective detection principles are also mentioned. Different instrumental configurations are discussed both with respect to technical set-up and performance, the principal reasons for halogen-selective detection are highlighted, and recent applications are reviewed from areas such as environmental chemistry, petroleum characterization, and drug analysis.     

Two-dimensional supercritical fluid chromatography/mass spectrometry for the enantiomeric analysis and purification of pharmaceutical samples

A new analytical two-dimensional supercritical fluid chromatography/mass spectrometry system (2D SFC/SFC/MS) has been designed and implemented to enhance the efficiency and quality of analytical support in drug discovery. The system consists of a Berger analytical SFC pump and a modifier pump, a Waters ZQ 2000 mass spectrometer, a set of switching valves, and a custom software program. The system integrates achiral and chiral separations into a single run to perform enantiomeric analysis and separation of a racemic compound from a complex mixture without prior clean up. The achiral chromatography in the first dimension separates the racemate from all other impurities, such as un-reacted starting materials and by-products. Mass-triggered fractionation is used to selectively fractionate the targeted racemic compound based on its molecular weight. The purified racemate from the achiral chromatography in the first dimension is then transferred to the chiral column in the second dimension to conduct the enantiomeric separation and analysis. A control software program, we coined SFC2D, was developed and integrated with MassLynx to retrieve acquisition status, current sample information, and real time mass spectrometric data as they are acquired. The SFC2D program also monitors the target ion signal to carry out mass-triggered fractionation by switching the valve to fractionate the desired peak. The 2D SFC/SFC/MS system uses one CO(2) pump and one modifier pump for both first and second dimension chromatographic separations using either gradient or isocratic elution. Similarly, a preparative 2D SFC/SFC/MS system has been constructed by modifying an existing Waters preparative LC/MS system. All components except the back pressure regulator are from the original LC/MS system. Applications of the 2D SFC/SFC/MS methods to the separation and the analysis of racemic pharmaceutical samples in complex mixtures demonstrated that an achiral separation (in first dimension) and a chiral separation (in second dimension) can be successfully combined into a single, streamlined process both in analytical and preparative scale.     

Liquid-phase microextraction for sample preparation in analysis of unconjugated anabolic steroids in urine

The applicability of in-vial two-phase liquid-phase microextraction (LPME) in porous hollow polypropylene fiber was studied for the sample preparation of unconjugated anabolic steroids in urine. Four different anabolic steroids - metabolites of fluoxymesterone, 4-chlorodehydromethyltestosterone, stanozolol and danazol - were used as test compounds and methyltestosterone as an internal standard. A standard two-phase LPME method for use with liquid chromatography/mass spectrometry (LC/MS) was set up and the influence of different parameters, including the nature of organic solvent, extraction time, salting-out and temperature, on the LPME process was investigated. Taking advantage of the preliminary studies, a novel two-phase LPME method utilizing simultaneous in-fiber silylation was developed and validated for gas chromatographic/mass spectrometric (GC/MS) analysis of a danazol metabolite in urine. In all, LPME allowed a very straightforward, simple and selective way to prepare urine samples for steroid analysis, being most suitable for hydrophobic steroids. The LPME method with in-fiber derivatization for GC/MS analysis exhibited high sensitivity, repeatability and linearity and enabled simultaneous filtration, extraction, enrichment and derivatization of the analyte from urine matrix without any other steps in sample pretreatment.     

Physicochemical Principles and Applications of Supercritical Fluid Chromatography (SFC). New analytical methods (19)

In supercritical fluid chromatography (SFC) compressed gases in the region of their critical temperature are used as mobile phases. SFC has important advantages over gas chromatography (GC) for the separation of low-volatile or thermally unstable substances. Like high pressure liquid chromatography (HPLC) and gel chromatography, it is used for various special applications and preparative separations, e.g. in the petroleum industry and in the separation of oligomers. SFC is of great interest in fundamental research on fluid extraction and for the determination of the physicochemical properties of fluid systems. In this contribution the most important physicochemical, methodological, and instrumental principles of SFC are summarized; characteristic physicochemical applications are the determination of capacity ratios, partition coefficients, partial molar volumes, interaction second virial coefficients, and difusion coefficients.