Capillary electrophoresis/mass spectrometry relevant to pharmaceutical and biotechnological applications

Advanced analytical techniques play a crucial role in the pharmaceutical and biotechnological field. In this context, capillary electrophoresis/mass spectrometry (CE/MS) has attracted attention due to efficient and selective separation in combination with powerful detection allowing identification and detailed characterization. Method developments and applications of CE/MS have been focused on questions not easily accessible by liquid chromatography/mass spectrometry (LC/MS) as the analysis of intact proteins, carbohydrates, and various small molecules, including peptides. Here, recent approaches and applications of CE/MS relevant to (bio)pharmaceuticals are reviewed and discussed to show actual developments and future prospects. Based on other reviews on related subjects covering large parts of previous works, the paper is focused on general ideas and contributions of the last 2 years; for the analysis of glycans, the period is extended back to 2006.     

Applications of solid‐phase micro‐extraction with mass spectrometry in pesticide analysis

Pesticides, widely applied in agriculture, can produce a variety of transformation products and their continuous use causes deleterious effects to ecosystem. Efficient and sensitive analytical techniques for enrichment and analysis of pesticides samples are highly required. Compared with other extraction methods, solid‐phase micro extraction is a solvent free, cost effective, robust, versatile, and high throughput sample preparation technique, especially for the analysis of pesticides from complicated matrices. Coupling of solid‐phase micro extraction with gas chromatography and mass spectrometry and liquid chromatography–mass spectrometry has been extensively applied in pesticide analysis. On the other hand, in recent years, combination of fast separation using solid‐phase micro extraction and rapid detection using ambient mass spectrometry is providing highly efficient pesticide screening. This article summarizes the applications of solid‐phase micro extraction coupled to mass spectrometry for pesticides analysis.     

窄内径多孔层开管柱的制备及在液相色谱中的应用

近年来,微纳分离技术由于其内在的优势而受到越来越多的关注.多孔层开管柱是一种重要的微分离柱形式,与粗内径的多孔层开管柱(>25μm)相比,窄内径的多孔层开管柱具有更高的分离效率和更低的试剂消耗量.本文综述了内径≤25μm的窄内径多孔层开管毛细管柱的制备方法、与质谱检测联用技术以及在液相色谱中的应用研究进展,对其发展前景进行了展望.     

Liquid-phase microextraction with porous hollow fibers, a miniaturized and highly flexible format for liquid-liquid extraction

Since 1999, substantial research has been devoted to the development of liquid-phase microextraction (LPME) based on porous hollow fibers. With this technology, target analytes are extracted from aqueous samples, through a thin supported liquid membrane (SLM) sustained in the pores in the wall of a porous hollow fiber, and further into a microL volume of acceptor solution placed inside the lumen of the hollow fiber. After extraction, the acceptor solution is directly subjected to a final chemical analysis by liquid chromatography (HPLC), gas chromatography (GC), capillary electrophoresis (CE), or mass spectrometry (MS). In this review, LPME will be discussed with focus on extraction principles, historical development, fundamental theory, and performance. Also, major applications have been compiled, and recent forefront developments will be discussed.     

Coupling of CE‐MS for protein and peptide analysis

The review is focused on the latest developments in the analysis of proteins and peptides by capillary electrophoresis techniques coupled to mass spectrometry. First, the methodology and instrumentation are overviewed. In this section, recent progress in capillary electrophoresis with mass spectrometry interfaces and capillary electrophoresis with matrix‐assisted laser desorption/ionization is mentioned, as well as separation tasks. The second part is devoted to applications—mainly bottom‐up and top‐down proteomics. It is obvious that capillary electrophoresis with mass spectrometry methods are well suited for peptide and protein analysis (proteomic research) and it is described how these techniques are complementary and not competitive with the often used liquid chromatography with mass spectrometry methods.     

Microfluidic Pressure Driven Liquid Chromatography of Biologically Relevant Samples

An overview of the literature regarding the most recent and innovative developments in microfluidic devices for pressure-driven chromatographic separations is given, with a focus on proteomics and metabolomics applications. The applications can be considered as the main driving force for the developments in this research field, since they put high demands on the analytical technology such as for throughput, efficiency, and sensitivity and for the possibilities to interface with mass spectrometry. The developments are evaluated based on the feasibility for use in work flows for the analysis of biologically relevant samples. The literature up to the first half of 2011 is covered. Electrophoretic separations are not within the scope of this review. Several strategies have been described to obtain a retentive phase in microfluidic channels. Open channels with the stationary phase bound to the walls appear to be relatively easy to make. However, the retention in such channels is generally very low for separations of relevant samples. Microfabrication of perfectly ordered topographic structures is the most innovative of the methods discussed for the creation of stationary phases in narrow channels. Several groups work on the improvement of the surface-to-volume ratio in such channels, using different methods, and the developments towards real applications are promising. Channels packed with spherical particles and in situ polymerized monoliths for pressure-driven separations are the most frequently applied. Microfluidic devices with an integrated injection system, a (packed) separation column and a spray tip for coupling to a mass spectrometer are already commercially available, and used in practice in proteomics and metabolomics. Finally, the inherent advantages of microfluidic devices for multidimensional separations have been shown in practice in a number of studies. In these studies, pressure-driven chromatography is coupled (in series or multiplexed) to an electrophoretic separation method. The high peak capacity of such 2-dimensional separations has been shown.

     

Capillary electrophoresis-mass spectrometry for intact protein analysis: Pharmaceutical and biomedical applications (2018–March 2023)

Capillary electrophoresis is recognized as a valued separation technique for its high separation efficiency, low sample consumption, good economic and ecological aspects, reproducibility, and complementarity to traditional liquid chromatography techniques. Capillary electrophoresis experiments are generally performed utilizing optical detection, such as ultraviolet or fluorescence detectors. However, in order to provide structural information, capillary electrophoresis hyphenated to highly sensitive and selective mass spectrometry has been developed to overcome the limitations of optical detections. Capillary electrophoresis-mass spectrometry is increasingly popular in protein analysis, including biopharmaceutical and biomedical research. It is frequently applied for the determination of physicochemical and biochemical parameters of proteins, offers excellent performance for in-depth characterizations of biopharmaceuticals at various levels of analysis, and has been also already proven as a promising tool in biomarker discovery. In this review, we focus on the possibilities and limitations of capillary electrophoresis-mass spectrometry for protein analysis at their intact level. Various capillary electrophoresis modes and capillary electrophoresis-mass spectrometry interfaces, as well as approaches to prevent protein adsorption and to enhance sample loading capacity, are discussed and the recent (2018–March 2023) developments and applications in the field of biopharmaceutical and biomedical analysis are summarized.     

Silica-based monoliths for rapid peptide screening by capillary liquid chromatography hyphenated with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Capillary liquid chromatography based on particulate and monolithic stationary phases was used to screen complex peptide libraries by fast gradient elution coupled on-line to electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS). A slightly modified commercial electrospray interface consisting of a fused-silica transfer capillary and low dead volume stainless steel union at which the electrospray voltage was grounded enabled the effluent of all the capillary columns to be directly sprayed into the mass spectrometer. Stable electrospray conditions were generated over a wide range of mobile phase compositions, alleviating the need for a tapered end of the spray capillary, pneumatic assistance or preheated nebulizer gas. Since the identification of complex samples containing numerous isobaric substances is facilitated by chromatographic separation prior to mass spectrometry, stationary phase materials have been employed which offer a fast, efficient elution and, due to the complexity of samples, a high loading capacity. Silica-based monolithic capillary columns combine these three characteristics in a unique manner due to a tailored adjustment of both macro- and mesopore sizes in the highly porous silica structure. As we demonstrate by a comparative study of the silica-based monolithic and packed capillaries for LC/MS analysis of complex peptide libraries, silica monoliths show superior performance over packed beds of small-diameter particles with respect to analysis time and separation efficiency. Libraries with more than 1000 different peptides could be screened in less than 20 min.     

Properties of the Adsorption Equilibrium Isotherms Used and Measured in RPLC

Monitoring anabolic steroids in meat-producing animals is a challenging task. It implies very specific and sensitive analytical methods able to detect and identify sub-μg kg^?1 residue levels in complex biological matrices such as meat, urine, or hair. Gas and liquid chromatography coupled to mass spectrometry are the most efficient means of achieving these objectives. In this paper we review how developments in mass spectrometry have been rapidly applied to this problem, how efficient analysis of anabolic steroids in urine, edible tissue, and hair has been achieved, and, later, how measurement of conjugate steroids and determination of the origin of natural steroid hormones has been achieved. The performance characteristics of different mass spectrometers (quadrupole, ion-trap, electromagnetic, isotope-ratio, tandem, and hybrid instruments), the efficiency of different acquisition techniques (LR-SIM, HR-SIM, MRM), and, finally, sample introduction (gas chromatography and liquid chromatography, with discussion of alternative interfaces) are discussed, with numerous applications.     

色谱-质谱联用技术在代谢组学中的应用

代谢组学是对生物体受外部刺激所产生的小分子代谢产物的变化或其随时间的变化进行研究的一门学科,以实现对体液、细胞以及组织提取物等复杂的生物样本中所有代谢产物的定性和定量分析为研究目标。色谱-质谱联用技术在代谢组学的研究中已显示出极大的发展潜力。本文主要综述近年来代谢组学研究中涉及的色谱-质谱联用技术及其数据处理方法,重点介绍各种分离技术的特点及其在应用中的关键问题,并对其在代谢组学应用中的未来发展给予展望。     

Multiresidue analysis of quinolones in water by ultra‐high perfomance liquid chromatography with tandem mass spectrometry using a simple and effective sample treatment

A rapid and simple analytical method has been developed for the determination of 19 quinolones in environmental water samples using ultra high performance liquid chromatography with tandem mass spectrometry. Chromatographic and detection conditions have been optimized and the separation was achieved in less than 4 min. The separation was carried out using a new‐generation column filled with superficially porous particles, resulting in lower backpressure and better resolution than totally porous particle columns. The quinolones were detected by electrospray ionization in positive mode using multiple‐reaction monitoring mode for acquisition. A sample treatment based on liquid–liquid extraction and phase separation via salting‐out was employed to achieve a fast and simple extraction that enables the multiresidue analysis. The method has been validated for an environmental well water sample from a mountain area. Very low limits of detection (between 10 and 90 ng/L) with relative standard deviations lower than 16.5% and recoveries higher than 73% were achieved. Moreover, well waters from different origins (mountain and coast areas and irrigated land) have been evaluated and similar results were obtained.     

快速气相色谱法分析石油饱和烃

提出了一种快速分析原油和岩石抽提物中饱和烃组分的毛细管气相色谱(GC)方法。由于在该方法中采用了细内径毛细管柱,故饱和烃的GC分析周期由原来的80~90 min缩短至15 min,分析速度加快约5倍,大大提高了工作效率和仪器通量,使石油饱和烃得到了很好的分离分析。该方法符合中华人民共和国石油天然气行业标准SY/T5120-1997的要求。20万理论塔板数的细径柱的应用,可供石油中异构烷烃,尤其是甾烷、萜烷类的气相色谱/质谱(GC/MS)快速分析方法及芳烃的GC快速分析方法借鉴。     

Chemiluminescence aptasensor for cocaine based on double-functionalized gold nanoprobes and functionalized magnetic microbeads

This year inductively coupled plasma mass spectrometry (ICP-MS) moves into the fourth decade of development. In this article, some recent trends and developments in ICP-MS are reviewed, with special focus on instrumental development and emerging applications. Some key trends include a novel mass spectrometer for elemental and speciation analysis in Mattauch–Herzog geometry with a focal-plane-camera array detector. The reason for this development is the possibility to record the full elemental mass range simultaneously and all the time. Monitoring fast transient signals in chromatography or laser ablation is now possible and will become an important asset in future studies, e.g., for isotope ratio analysis. In addition, there is a lot of new activity and interest in the area of nanosciences and medicine. Here, instrumental developments are reported that allow the direct analysis of microparticles and single cells.     

整体柱制备技术的新进展及其在蛋白质组学中的应用

整体柱是通过在柱管内原位聚合或固化的方法制备得到的具有多孔结构的整体棒状固定相,与传统的填充柱相比,具有通透性好、传质速率快、容易制备等优点,因此在分离分析领域特别是生物分离分析中发挥的作用日益增大。整体柱的制备及应用近年来也得到了快速发展,层出不穷的新型整体柱已被广泛用于色谱高效分离分析、固相萃取及酶反应器等方面,大大推动了分离分析科学的发展。本文主要总结了近五年来整体柱的制备技术及其在蛋白质组学应用中的一些最新研究进展。     

基于色谱法与质谱法分析唾液酸的衍生方法的研究进展

唾液酸是一类拥有9碳核心结构的单糖,广泛存在于脊椎动物体内,以及部分无脊椎动物、真菌和细菌中。唾液酸在生物体内可以以游离形式存在,也经常作为重要的组成部分连接于糖缀合物的末端,这使得其能够参与到多项生理活动中,且与炎症、癌症等疾病密切相关。以色谱法、质谱法为核心的分析方法,是表征生物样品中唾液酸的最主要研究方法。为了提高检测灵敏度或色谱分离度,在分析之前通常需要对唾液酸进行衍生化处理。经过几十年的发展,研究者们逐步建立了多种衍生化方法。该文从单糖、自由唾液酸、N/O-聚糖、糖脂的角度综述了用于色谱与质谱分析唾液酸的衍生方法,并展望了该领域的应用及发展趋势。     

An Introduction to Monolithic Disks as Stationary Phases for High Performance Biochromatography

Monolithic stationary phases have revolutionized protein chromatography because they combine speed, capacity, and resolution in a unique manner. Since such stationary phases contain no particles but only flow‐through pores, the usual mass transfer restrictions to the chromatography of large molecules are not observed and extremely fast separations become possible. Recently the area of application of monolith chromatography has been extended to the separation and analysis of small molecules and plasmid DNA. This review summarizes the state of art in high performance monolith and especially high performance monolithic disk chromatography (HPMDC). The current understanding of the theory of protein HPMDC is summarized, while an introduction to the evolving field of small molecule HPMDC is attempted. The basic differences between the monolithic disks and columns packed with conventional stationary phases (including perfusion and micropellicular particles) but also monolithic columns (porous rods) are outlined. Finally, the potential of HPMDC to analytical and preparative biochromatography is demonstrated by a discussion of recent applications of chromatographic disks for protein isolation and bioprocess analysis.     

Recent developments in the characterization of nucleic acids by liquid chromatography,capillary electrophoresis,ion mobility,and mass spectrometry (2010–2020)

The development of new strategies for the analysis of nucleic acids has gained momentum due to the increased interest in using these biomolecules as drugs or drug targets. The application of new mass spectrometry ion activation techniques and the optimization of separation methods including liquid chromatography, capillary electrophoresis, and ion mobility have allowed more detailed characterization of nucleic acids and oligonucleotide therapeutics including confirmation of sequence, localization of modifications and interaction sites, and structural analysis as well as identification of failed sequences and degradation products. This review will cover tandem mass spectrometry methods as well as the recent developments in liquid chromatography, capillary electrophoresis, and ion mobility coupled to mass spectrometry for the analysis of nucleic acids and oligonucleotides.     

Recent developments in DNA adduct analysis using liquid chromatography coupled with mass spectrometry

The formation of DNA adducts by genotoxic agents is an early event in cancer development, and it may lead to gene mutations, thereby initiating tumor development. The measurement of DNA adducts can provide critical information about the genotoxic potential of a chemical and its mechanism of carcinogenesis. In recent decades, liquid chromatography coupled with mass spectrometry has become the most important technique for analyzing DNA adducts. The improvements in resolution achievable with new chromatographic separation techniques coupled with the high specificity and sensitivity and wide dynamic range of new mass spectrometry systems have been used for both qualitative and quantitative analyses of DNA adducts. This review discusses the challenges in qualitative and quantitative analyses of DNA adducts by liquid chromatography coupled with mass spectrometry and highlights recent developments towards overcoming the limitations of liquid chromatography coupled with mass spectrometry methods. The key steps and new solutions, such as sample preparation, mass spectrometry fragmentation, and method validation, are summarized. In addition, the fundamental principles and latest advances in DNA adductomic approaches are reviewed.     

Synthesis of penetrable macroporous silica spheres for high-performance liquid chromatography

Silica microspheres have been synthesized by phase separation and sol–gel transition coupled with emulsion method. The as-obtained material is characterized by scanning electron microscopy, nitrogen sorption, elemental analysis and particle size distribution measurements. The results demonstrated that the material featured with hierarchically porous structure, possessing both mesopores and penetrable macropores. The mesopores provide large surface area while the macropores traverse the silica particles, which may facilitate fast mass transfer as well as guarantee low backpressure when such materials are used for packed high-performance liquid chromatography (HPLC) column. Therefore, their preliminary applications as HPLC packings in fast separation and low-pressure separation have been attempted in the present study. Benzene, benzaldehyde and benzyl alcohol were separated within two minutes on the silica column at a flow rate of 7 mL min⁻¹. Vitamin E mixtures can also be baseline separated at a high flow rate of 8 mL min⁻¹. In addition, thirteen aromatic hydrocarbons were well separated on the octadecyl-bonded silica (ODS) column. In comparison with a commercial Kromasil ODS column, the pressure of the proposed column is much lower (<1/2) under the same chromatographic conditions, while comparable separation efficiency can be achieved.     

Photo-induced chemical-vapor generation for sample introduction in atomic spectrometry

Chemical-vapor generation (CVG) is widely used as a sample-introduction technique for atomic spectrometry, with the advantages of efficient matrix separation, high analyte-transport efficiency, and high selectivity and sensitivity. Recently, photo-induced CVG (photo-CVG) was demonstrated to be a powerful alternative to conventional CVG. In photo-CVG, volatile species (including hydrides, elemental, carbonylated and alkylated analytes) are generated from non-volatile precursors by ultraviolet irradiation in the presence of low-molecular-weight organic compounds. Photo-CVG is simple, fast and environmentally friendly with little interference from transition metals. Its analytical applications have been demonstrated in analysis of Hg, conventional hydride-forming elements (As, Bi, Sb, Se, Te), transition metals (Ni, Co, Fe) and non-metals (I). In addition, photo-CVG was developed as a simple, effective interface between high-performance liquid chromatography (HPLC) and atomic spectrometry. This review summarizes the applications of photo-CVG for various analytes and as a novel interface between HPLC and atomic spectrometry. We also discuss current research on the possible reaction mechanism of photo-CVG.