Determination of oxaliplatin enantiomers at attomolar levels by capillary electrophoresis connected with inductively coupled plasma mass spectrometry

Characterization of Nanoparticles in Mixtures by Taylor Dispersion Analysis Hyphenated to Inductively Coupled Plasma Mass Spectrometry

A novel methodology for investigating the behavior of nanoparticles in their mixtures in aqueous high-ionic strength conditions is presented in this work. Our approach utilizes Taylor dispersion analysis in capillaries connected to inductively coupled plasma mass spectrometry (ICP-MS) to probe metal-derived nanoparticles. This methodology simultaneously distinguishes between different kinds of nanoparticles and accurately determines their essential parameters, such as hydrodynamic size, diffusion coefficient, and elemental composition. Moreover, the isotope-specific ICP-MS detection allows for unique targeting of the fate of isotopically enriched nanoparticles. The complexity of our methodology opens the way for studying barely explored areas of interparticle interactions or unequivocal characterization of one type of nanoparticle in complex mixtures without any need for calibration as well as labor-consuming sample preparation.

Capillary Electrophoresis Mass Spectrometry: Developments and Applications for Enantioselective Analysis from 2011–2020

It is now more than 25 years since the first report of enantioselective analysis by capillary electrophoresis-mass spectrometry (CE-MS) appeared. This article reviews the power of chiral CE-MS in resolving issues on the use of chiral selector incompatibility with MS and poor detectability encountered for chiral compounds by UV detection. The review begins with the general principles, requirements, and critical aspects of chiral CE-MS instrumentation. Next, the review provides a survey of MS-compatible chiral selectors (CSs) reported during the past decade, and the key achievements encountered in the time period using these CSs. Within the context of the strategies used to combine CE and MS, special attention is paid to the approaches that feature partial filling technique, counter-migration techniques, and direct use of CS, such as molecular micelles. In particular, the development and application of moving and fixed CS for EKC-MS, MEKC-MS, and CEC-MS demonstrate how various chiral compounds analyses were solved in a simple and elegant way during the 2010–2020 review period. The most noteworthy applications in the determination of chiral compounds are critically examined. The operating analytical conditions are detailed in the Tables, and the authors provide commentary on future trends of chiral separations by CE-MS.

Microalgae as an Effective Recovery Agent for Vanadium in Aquatic Environment

Given that vanadium is a valuable material, the implementation of vanadium recycling processes is thus necessary to enhance the element’s value chain as well as minimize its undesirable environmental consequences. Among various remediation methods available, a biological method based on microalgal adsorption is known to be eco-friendly and calls for further investigations. Herein, we evaluated V2O5 adsorption efficiencies of four different microalgal strains: Nannochloropsis oculata, Heterocapsa circularisquama, Chattonella marina, and Chattonella antiqua. Inductively coupled plasma mass spectrometry (ICP-MS) data indicated that vanadium concentration in the culture medium of Nannochloropsis oculata was reduced from 4.61 ± 0.11 mg L−1 to 1.85 ± 0.21 mg L−1 after being exposed to V2O5 solution for 24 h, whereas the supernatants of the other three strains displayed no change in vanadium ion concentration. Therefore, our results indicated a strong potential of Nannochloropsis oculata for recycling vanadium with approximately 59.9% of vanadium ion removal efficiency. Furthermore, morphological observation of Nannochloropsis oculata using scanning electron microscopy (SEM) indicated that the cells were able to maintain their intact morphology even under the presence of high concentrations of heavy metals. Due to the high adsorption efficiency and robustness of Nannochloropsis oculata, the results collectively support it as a potential strain for V2O5 recovery.

Advances in chiral separation and analysis by capillary electrophoresis-mass spectrometry

目前使用的绝大多数药物为手性化合物,它们具有相似的物理和化学性质,但药理活性不同,且常以外消旋混合物的形式存在,因此对手性化合物的分离在生物、环境、食品和医药等领域一直备受关注。与广泛使用的液相色谱-质谱(LC-MS)相比,毛细管电泳-质谱(CE-MS)作为一种新型分离分析技术,具有分离效率高、样品和试剂消耗量低、选择性高和分离模式多样化等诸多优势,已经发展成为手性分析领域中有广阔应用前景的分析方法之一。CE-MS结合了CE的高分离效率和低样品消耗以及MS的高灵敏度和强结构解析能力,在蛋白质组学和代谢组学等领域发挥了重要作用。CE杰出的手性拆分能力与MS优势的结合,亦使CE-MS成为实现手性化合物高效分离分析的完美组合。在过去的十几年里,基于不同CE-MS分离模式的高性能手性分析体系层出不穷,如电动色谱-质谱(EKC-MS)、胶束电动色谱-质谱(MEKC-MS)和毛细管电色谱-质谱(CEC-MS)等,并成功应用于医药、生物、食品和环境科学等领域的手性化合物分析。该文主要综述了2011~2021年,CE-MS在手性化合物分析领域的技术、手性选择剂(如改性环糊精和聚合物表面活性剂等)的使用以及在医药等领域应用方面的研究进展,并讨论了不同手性分析模式的局限性,为未来的CE-MS手性分离分析技术发展及应用提供借鉴。

Sensitivity enhancement in capillary electrophoresis and their applications for analyses of pharmaceutical and related biochemical substances

This review aims to illustrate sensitivity enhancement methods in capillary electrophoresis (CE) and their applications for pharmaceutical and related biochemical substance analyses. The first two parts of the article describe the introduction and principle of CE. The main part focuses on strategies for sensitivity improvement in CE including detector and capillary technologies and pre-concentration techniques. Applications of these techniques for pharmaceutical and biomedical substance analyses are surveyed during the years 2018-2021. This article is protected by copyright. All rights reserved.

Analytical methods for the quantification of cisplatin, carboplatin, and oxaliplatin in various matrices over the last two decades

Background:

Platinum derivatives including cisplatin and its later generations carboplatin, and oxaliplatin remain the most largely used drugs in the therapy of malignant diseases. They exert notable anticancer activity towards numerous types of solid tumors such as gastric, colorectal, bladder, ovary, and several others. The chemotherapeutic activity of these compounds, however, is associated with many unwanted side effects and drug resistance problems limiting their application and effectiveness. Proper dosage is still an inherent problem, as these drugs are usually prescribed in small doses.

Objective:

Several analytical methods have been reported for the accurate quantification of cisplatin, carboplatin, and oxaliplatin and their metabolites either alone or in combination with other chemotherapeutic drugs, in different matrices such as pharmaceutical formulations, biological fluids, cancer cells, and environmental samples. The main goal of this review is to systematically study the analytical methods already used for the analysis of cisplatin, carboplatin, and oxaliplatin in various matrices during the last two decades.

Results and Conclusion:

In the literature, reviews showed that numerous analytical methods such as electroanalytical, UV-visible spectrophotometry, chromatographic, fluorescence, atomic absorption spectrophotometry, and other spectroscopic methods combined with mass spectrometry were used for the determination of these compounds in various matrices.

Current applications of capillary electrophoresis-mass spectrometry for the analysis of biologically important analytes in urine (2017 to mid-2021): A review

Capillary electrophoresis coupled online with mass detection is a modern tool for analyzing wide ranges of compounds in complex samples, including urine. Capillary electrophoresis with mass spectrometry allows the separation and identification of various analytes spanning from small ions to high molecular weight protein complexes. Similarly to the much more common liquid chromatography‐mass spectrometry techniques, the capillary electrophoresis separation reduces the complexity of the mixture of analytes entering the mass spectrometer resulting in reduced ion suppression and a more straightforward interpretation of the mass spectrometry data. This review summarizes capillary electrophoresis with mass spectrometry studies published between the years 2017 and 2021, aiming at the determination of various compounds excreted in urine. The properties of the urine, including its diagnostical and analytical features and chemical composition, are also discussed including general protocols for the urine sample preparation. The mechanism of the electrophoretic separation and the instrumentation for capillary electrophoresis with mass spectrometry coupling is also included. This review shows the potential of the capillary electrophoresis with mass spectrometry technique for the analyses of different kinds of analytes in a complex biological matrix. The discussed applications are divided into two main groups (capillary electrophoresis with mass spectrometry for the determination of drugs and drugs of abuse in urine and capillary electrophoresis with mass spectrometry for the studies of urinary metabolome).

In-situ growth of a spherical vinyl-functionalized covalent organic framework as stationary phase for capillary electrochromatography-mass spectrometry analysis

Column technology is an important part in capillary electrochromatographic science. Developing novel stationary phase with high separation efficiency and high loading capacity is an essential work. In this work, a novel spherical vinyl-functionalized covalent-organic framework (COF-V) was synthesized at room temperature and firstly employed as stationary phase for CEC-MS analysis. The COF-V based CEC column was characterized by scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The results proved the successful modification of COF-V. The COF-V based column possesses the advantages like strong electroosmotic flow, high separation efficiency and high loading capacity. The CEC column showed powerful separation selectivity to several kinds of compounds, and the highest column efficiency (theoretical plates, N) was over 1.4 × 10⁵ plates·m^-1 for methylbenzene. Besides, the COF-V modified column exhibited excellent repeatability and stability. The relative standard deviations (RSDs) of retention times for intra-day (n = 5), inter-day (n = 3) runs and column-to-column (n = 3) were all less than 2.1%. Hence, the COF-V modified column was successfully applied in CEC-MS for determination of antiepileptic drug, triazine herbicides and active ingredients in traditional Chinese medicine.

Chiral Capillary Electrokinetic Chromatography: Principle and Applications, Detection and Identification, Design of Experiment, and Exploration of Chiral Recognition Using Molecular Modeling

This work reviews the literature of chiral capillary electrokinetic chromatography from January 2016 to March 2021. This is done to explore the state-of-the-art approach and recent developments carried out in this field. The separation principle of the technique is described and supported with simple graphical illustrations, showing migration under normal and reversed polarity modes of the separation voltage. The most relevant applications of the technique for enantioseparation of drugs and other enantiomeric molecules in different fields using chiral selectors in single, dual, or multiple systems are highlighted. Measures to improve the detection sensitivity of chiral capillary electrokinetic chromatography with UV detector are discussed, and the alternative aspects are explored, besides special emphases to hyphenation compatibility to mass spectrometry. Partial filling and counter migration techniques are described. Indirect identification of the separated enantiomers and the determination of enantiomeric migration order are mentioned. The application of Quality by Design principles to facilitate method development, optimization, and validation is presented. The elucidation and explanation of chiral recognition in molecular bases are discussed with special focus on the role of molecular modeling.

A review on analytical methods with special reference to electroanalytical methods for the determination of some anticancer drugs in pharmaceutical and biological samples

It is widely accepted that cancer, the second leading cause of death, is a morbidity with big impacts on the global health. In the last few years, chemo-therapeutic treatment continually induces alone most lengthy consequents, which is extremely harmful for the physiological and psychological health of the patients. In the present research, we discuss the recent techniques for employed for extraction, and quantitative determination of such compounds in pharmaceutical, and biological specimens. In the frame of this information, this review aims to provide basic principles of chromatography, spectroscopy, and electroanalytical methods for the analysis of anticancer drugs published in the last three years. The review also describes the recent developments regarding enhancing the limit of detection (LOD), the linear dynamic range, and so forth. The results show that the LOD for the chromatographic techniques with the UV detector was obtained equaled over the range 2.0 ng mL^-1-0.2 μg mL^-1, whereas the LOD values for analysis by chromatographic technique with the mass spectrometry (MS) detector was found between 10.0 pg mL^-1-0.002 μg mL^-1. The biological fluids could be directly injected to capillary electrophoresis (CE) in cases where the medicine concentration is at the contents greater than mg L^-1 or g L^-1. Additionally, electrochemical detection of the anticancer drugs has been mainly conducted by the voltammetry techniques with diverse modified electrodes, and lower LODs were estimated between 3.0 ng mL^-1-0.3 μg mL^-1. It is safe to say that the analyses of anticancer drugs can be achieved by employing a plethora of techniques such as electroanalytical, spectroscopy, and chromatography techniques.

Discrimination of isomeric monosaccharide derivatives using collision-induced fingerprinting coupled to ion mobility mass spectrometry

Because of the isomeric heterogeneity that is ubiquitous in analytical science, a formidable analytical challenge is to fully discriminate multiple isomers, especially those candidate isomers with various biological functions. Ion mobility mass spectrometry (IM-MS) has gained impressive advances for gaining molecular conformations, whereas coexisting structurally similar isomers often make unambiguous discrimination impossible due to the limited IM resolution of commercially available instruments. Herein, we demonstrate an energy-resolved collision-induced fingerprint (CIF) method to fully discriminate isomeric monosaccharide derivatives that differ in terms of composition, connectivity and configuration without complex instrument modifications. By simply increasing the collisional energy in the trap cell, the full width at half maximum (FWHM) of IM peaks can be markedly narrowed by at least 2-fold. Given the excellent reproducibility of CIF measurements, the full discrimination of isomers can benefit from their unique feature values and root-mean square deviation (RMSD) in CIF spectra. Moreover, rapid discrimination of each monosaccharide derivate isomer from binary mixtures is demonstrated. This strategy will expand the horizons of IM-MS platform in the rapid differentiation of a wider range of isomers more than monosaccharide derivatives in complex systems, which facilitates the identification and evaluation of innovative isomer candidates with unexplored functions.

Past, present, and future developments in enantioselective analysis using capillary electromigration techniques

Enantioseparation of chiral products has become increasingly important in a large diversity of academic and industrial applications. The separation of chiral compounds is inherently challenging and thus requires a suitable analytical technique that can achieve high resolution and sensitivity. In this context, CE has shown remarkable results so far. Chiral CE offers an orthogonal enantioselectivity and is typically considered less costly than chromatographic techniques, since only minute amounts of chiral selectors are needed. Several CE approaches have been developed for chiral analysis, including chiral EKC and chiral CEC. Enantioseparations by EKC benefit from the wide variety of possible pseudostationary phases that can be employed. Chiral CEC, on the other hand, combines chromatographic separation principles with the bulk fluid movement of CE, benefitting from reduced band broadening as compared to pressure-driven systems. Although UV detection is conventionally used for these approaches, MS can also be considered. CE-MS represents a promising alternative due to the increased sensitivity and selectivity, enabling the chiral analysis of complex samples. The potential contamination of the MS ion source in EKC-MS can be overcome using partial-filling and counter-migration techniques. However, chiral analysis using monolithic and open-tubular CEC-MS awaits additional method validation and a dedicated commercial interface. Further efforts in chiral CE are expected toward the improvement of existing techniques, the development of novel pseudostationary phases, and establishing the use of chiral ionic liquids, molecular imprinted polymers, and metal-organic frameworks. These developments will certainly foster the adoption of CE(-MS) as a well-established technique in routine chiral analysis.

Negatively charged cyclodextrins: Synthesis and applications in chiral analysis-A review

The negatively charged cyclodextrins (CDs) play an important role in chiral analysis due to the additional electrostatic effect beyond the host-guest inclusion, especially in enantioanalysis of positively charged and electrically neutral analytes. This review presents recent advances in application of anionic CDs for enantioanalysis during the past five years. Firstly, the synthesis approaches of random substitution and single isomers of anionic CDs are briefly discussed. The main part focuses on the chiral analysis using anionic CDs in various analytical techniques, including capillary electrophoresis, high-performance liquid chromatography, capillary electrochromatography, counter current chromatography, nuclear magnetic resonance, etc. Particular attention is given to the capillary electrophoresis application since charged CDs could be used as a carrier of enantiomers by virtue of their self-mobility and offer an easy adjustment of the enantiomer migration order. Finally, future opportunities are also discussed in the conclusion of this review.

Visual chiral recognition of aromatic amino acids with (S)-mandelic acid-based ionic liquids via complexation

Recently, chiral ionic liquids have attracted increasing attention in analytical chemistry. However, only a few papers focus on the application of them in visual chiral recognition. Herein, two functionalized chiral ionic liquids derived from (S)-mandelic acid (1-butyl-3-methylimidazolium mandelate, CIL1 and N-butyl-N-methylpyrrolidinium mandelate, CIL2) were prepared for visual chiral recognition of aromatic amino acids for the first time. In the presence of Cu(II) and appropriate solvents, visual enantiomeric responses of phenylalanine, tryptophane, tyrosine and phenylglycine were observed. Relying on solubility or color differences, all chiral recognition could be finished within 5 min. The potential mechanism was investigated by means of infrared spectroscopy, ultraviolet spectroscopy, thermal gravity analysis, elemental analysis and scanning electron microscope. Results revealed that CuSO₄ interacted with CIL1 and D-tryptophane in the ratio of 1:1.96:0.43 in relevant precipitate, and the different stability of complex was responsible for the chiral recognition. In addition, resolution of racemic tryptophane was performed, which offered excellent enantiomeric excess values (94.2% for CIL1 and 95.1% for CIL2 in solid phase). The proposed ionic liquids had strong enantioselectivity for aromatic amino acids and great potential in visual chiral recognition.

Study of interactions between carboxylated core shell magnetic nanoparticles and polymyxin B by capillary electrophoresis with inductively coupled plasma mass spectrometry

In this work, interactions of carboxylated core shell magnetic nanoparticles with polymyxin B sulfate were studied by connecting capillary electrophoresis with inductively coupled plasma mass spectrometry. The interaction was probed by affinity mode of capillary electrophoresis with 25 mM phosphate buffer at physiological pH. ⁵⁴Fe, ⁵⁶Fe, ⁵⁷Fe, ³⁴S, and ¹²C isotopes were used to monitor the migration of an electroosmotic flow marker and the interaction of the nanoparticles with polymyxin B. The analysis of interaction data showed two distinct interaction regions, one with low polymyxin B concentration, the second with high polymyxin B concentration. These regions differed in the strength of the interaction, 1.49 × 10⁷ M^-1 and 1.60 × 10⁴ M^-1, and in the stoichiometry of 0.7 and 3.5, respectively. These differences can be explained by the decrease of electrostatic repulsion between nanoparticles caused by polymyxin B. This is also in agreement with the nanoparticles peak shapes: sharp for low polymyxin B concentrations and broad for high polymyxin B concentrations.