Journal of separation science最新文献

Monoclonal antibodies are biopharmaceuticals used to treat various diseases, including autoimmune disorders and cancer. Due to their structural complexity and inherent heterogeneity, robust analytical methods are required for their accurate quantification and quality control. This study presents a novel middle-up (MU) capillary zone electrophoresis-mass spectrometry (CZE-MS) method for the quantitative analysis of infliximab (IFX), a widely used therapeutic mAb. The method relies on disulfide bond reduction to separate heavy and light chains, followed by CZE separation using a 2 M acetic acid background electrolyte and MS detection in single ion monitoring mode. Adalimumab was used as an internal standard, providing a suitable alternative to isotopically labeled monoclonal antibody analogues. Evaluation of the analytical method performance followed ICH Q2(R1) guidelines and demonstrated an acceptable linearity range (4–35 µg/mL), precision, accuracy, and a limit of quantification of 4 µg/mL. The method was successfully applied to quantify IFX in a commercial pharmaceutical (Remicade). Moreover, the method was preliminarily tested for the quality control of bevacizumab in Avastin and rituximab in MabThera pharmaceutical formulations. To our knowledge, this is the first report of quantitative MU CZE-MS analysis of therapeutic monoclonal antibodies directly from pharmaceutical matrices, highlighting its potential for quality drug control applications.

Acanthopanax senticosus (AS) is a well-known traditional herbal medicine in China that can invigorate the spleen, tonify the qi and kidney, tranquilize the mind, and possess diverse bioactive functions. However, comprehensive and simultaneous analysis of the main active constituents from AS and in vivo metabolites remains underexplored, which severely impedes its further clinical application. In this study, AB-8 macroporous resin column chromatography was used to enrich the AS extract. Furthermore, ultrahigh performance liquid chromatography with quadrupole time of flight mass spectrometry (UHPLC–Q-TOF-MS/MS) and UPLC-Q-Orbitrap MS techniques were utilized to identify and characterize the chemical constituents and in vivo metabolites of AS extract, respectively. As a result, a total of 60 components were characterized in the AS extract, including 33 phenylpropanoids, 13 lignans, 4 coumarins, and 10 other substances. Additionally, a total of 29 prototype components and 226 metabolites were detected. Specifically, 91 metabolites were discovered in plasma, 19 in brain tissue, 111 in urine, and 76 in feces. The metabolic reactions included Phase I reactions (demethylation, deglucose, oxidation, and hydration) and Phase II reactions (methylation, sulfate esterification, glucuronidation, glucose conjugation, glycine conjugation, and acetylation). In conclusion, our findings provided basic data and a method for further investigations into the relationship between the chemical composition and pharmacological effects of AS. These results are valuable for revealing the material basis, illustrating the mechanism of medical action, and guiding the clinical applications of AS.

Acanthopanax senticosus (AS) is a well-known traditional herbal medicine in China that can invigorate the spleen, tonify the qi and kidney, tranquilize the mind, and possess diverse bioactive functions. However, comprehensive and simultaneous analysis of the main active constituents from AS and in vivo metabolites remains underexplored, which severely impedes its further clinical application. In this study, AB-8 macroporous resin column chromatography was used to enrich the AS extract. Furthermore, ultrahigh performance liquid chromatography with quadrupole time of flight mass spectrometry (UHPLC–Q-TOF-MS/MS) and UPLC-Q-Orbitrap MS techniques were utilized to identify and characterize the chemical constituents and in vivo metabolites of AS extract, respectively. As a result, a total of 60 components were characterized in the AS extract, including 33 phenylpropanoids, 13 lignans, 4 coumarins, and 10 other substances. Additionally, a total of 29 prototype components and 226 metabolites were detected. Specifically, 91 metabolites were discovered in plasma, 19 in brain tissue, 111 in urine, and 76 in feces. The metabolic reactions included Phase I reactions (demethylation, deglucose, oxidation, and hydration) and Phase II reactions (methylation, sulfate esterification, glucuronidation, glucose conjugation, glycine conjugation, and acetylation). In conclusion, our findings provided basic data and a method for further investigations into the relationship between the chemical composition and pharmacological effects of AS. These results are valuable for revealing the material basis, illustrating the mechanism of medical action, and guiding the clinical applications of AS.

Phenolic compounds, secondary metabolites, are essential products of plant metabolism. They are characterized by one or more aromatic rings attached to hydroxyl groups and are categorized into phenolic acids, flavonoids, tannins, stilbenes, and lignans. These compounds play critical roles in plants, contributing to pigmentation, astringency, UV protection, and defense against pests and pathogens. Widely distributed in fruits, vegetables, and other matrices, they are also extracted from waste and byproducts of the food production chain, aligning with sustainable practices. Research on phenolic compounds is extensive, driven by their significant health benefits and diverse biological activity. Extraction is the initial and critical step in their study, with efficiency influenced by factors such as the extraction method, plant matrix properties, solvent choice, temperature, pressure, and time. Recent years have seen a surge in studies on both conventional and innovative extraction methodologies, with a growing emphasis on green technologies. This review provides a comprehensive overview of advancements in green sample preparation (GSP) techniques within the framework of green analytical chemistry (GAC). It highlights strategies to minimize environmental impact, including the use of micro-techniques, assisted extraction methods, and eco-friendly solvents from renewable and non-toxic sources. Experimental design methods for optimizing phenolic compound yields are also discussed. Additionally, the review presents tools for assessing the greenness of sample preparation techniques, focusing on their environmental and operational improvements.

Okadaic acid is a fatty acid polyether biotoxin that poses a significant threat to global human health. In this work, a type of heterogeneous microporous organic network films was synthesized using a surface-initiated polymerization method, which was employed to control the growth of microporous organic network onto the bromine-functionalized surface of a polymer film. The resulting microporous organic network films feature a porous structure, a strong hydrophobic surface, excellent chemical stability, a large specific surface area, and abundant adsorption sites. These films were then applied in film-based solid-phase extraction, and showed outstanding extraction performance for okadaic acid. Under optimized conditions, the film-based solid-phase extraction method was combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to establish a new analytical method with high sensitivity and efficiency. The developed method offers a wide linear range (2.0–1000.0 pg mL⁻¹) with good linearity (r ≥ 0.9998), a low detection limit (0.5 pg mL⁻¹), and high precision (RSDs ≤ 5.2%, n = 5). This method was further utilized for the determination of okadaic acid in seafood, successfully detecting trace levels of okadaic acid (5.4 and 13.9 pg mL⁻¹) with satisfactory recoveries (85.4%–105.8%). The results indicate that the microporous organic network films hold great application potential in sample pretreatment, and provide a novel synthesis strategy for microporous organic network films.

A novel strategy combining XAD-4 macroporous resin pretreatment and online-storage inner-recycling high-speed counter-current chromatography (OS-IRCCC) was developed for efficient separation of multi-polarity constituents from Polygonatum cyrtonema Hua. The innovation lies in the OS-IRCCC mode, which integrates online storage of target fractions via a six-way valve-equipped recycling loop and inner-recycling separation, overcoming limitations of conventional high-speed counter-current chromatography in resolving structurally similar compounds. After resin fractionation, 40%, 60%, and 95% ethanol eluates were separated using methyl tert-butyl ether/n-butanol/acetonitrile/water (1:4:1:5, v/v) solvent system, chloroform/methanol/water (7:6:4, v/v) solvent system (with OS-IRCCC for Compounds 8 and 9), and petroleum ether/ethyl acetate/methanol/water (5:5:4:3, v/v) solvent system, respectively. Thirteen compounds were successfully isolated, including four high-polarity glycosides (1–4), five medium-polarity phenolic constituents (5–9), and four low-polarity terpenes (10–13). This study demonstrates that the established separation method provides an efficient, rapid, and straightforward approach for isolating active constituents from P. cyrtonema Hua.

A novel strategy combining XAD-4 macroporous resin pretreatment and online-storage inner-recycling high-speed counter-current chromatography (OS-IRCCC) was developed for efficient separation of multi-polarity constituents from Polygonatum cyrtonema Hua. The innovation lies in the OS-IRCCC mode, which integrates online storage of target fractions via a six-way valve-equipped recycling loop and inner-recycling separation, overcoming limitations of conventional high-speed counter-current chromatography in resolving structurally similar compounds. After resin fractionation, 40%, 60%, and 95% ethanol eluates were separated using methyl tert-butyl ether/n-butanol/acetonitrile/water (1:4:1:5, v/v) solvent system, chloroform/methanol/water (7:6:4, v/v) solvent system (with OS-IRCCC for Compounds 8 and 9), and petroleum ether/ethyl acetate/methanol/water (5:5:4:3, v/v) solvent system, respectively. Thirteen compounds were successfully isolated, including four high-polarity glycosides (1–4), five medium-polarity phenolic constituents (5–9), and four low-polarity terpenes (10–13). This study demonstrates that the established separation method provides an efficient, rapid, and straightforward approach for isolating active constituents from P. cyrtonema Hua.

An ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the simultaneous determination of fipronil and its three metabolites (fipronil sulfone, fipronil sulfide, and fipronil desulfinyl) in zebrafish tissues. Protein precipitation was employed for sample preparation, followed by chromatographic separation on a C₁₈ column. The method demonstrated excellent linearity (r² > 0.99) across a range of 0.1–10 ng/mL, with a lower limit of quantification (LLOQ) of 0.1 ng/mL for all analytes. Validation results confirmed acceptable accuracy (−5.0% to 8.9%), precision (0.6%–13.2%), recoveries (86.3%–113.6%), and minimal matrix effects (86.0%–110.6%). When applied to zebrafish exposed to 50 µg/L fipronil for 12 h, the method revealed preferential accumulation of fipronil and fipronil sulfone in liver tissues, while lower levels were detected in muscle tissues. Fipronil sulfide was rarely detected, and fipronil desulfinyl concentrations were below the LLOQ (0.1 ng/mL) in all tested samples. This reliable and sensitive method is well-suited for environmental toxicology studies, pesticide residue monitoring, and ecological risk assessment.

Phenolic compounds, secondary metabolites, are essential products of plant metabolism. They are characterized by one or more aromatic rings attached to hydroxyl groups and are categorized into phenolic acids, flavonoids, tannins, stilbenes, and lignans. These compounds play critical roles in plants, contributing to pigmentation, astringency, UV protection, and defense against pests and pathogens. Widely distributed in fruits, vegetables, and other matrices, they are also extracted from waste and byproducts of the food production chain, aligning with sustainable practices. Research on phenolic compounds is extensive, driven by their significant health benefits and diverse biological activity. Extraction is the initial and critical step in their study, with efficiency influenced by factors such as the extraction method, plant matrix properties, solvent choice, temperature, pressure, and time. Recent years have seen a surge in studies on both conventional and innovative extraction methodologies, with a growing emphasis on green technologies. This review provides a comprehensive overview of advancements in green sample preparation (GSP) techniques within the framework of green analytical chemistry (GAC). It highlights strategies to minimize environmental impact, including the use of micro-techniques, assisted extraction methods, and eco-friendly solvents from renewable and non-toxic sources. Experimental design methods for optimizing phenolic compound yields are also discussed. Additionally, the review presents tools for assessing the greenness of sample preparation techniques, focusing on their environmental and operational improvements.