Chromatographia最新文献

Dalbergia sissoo Roxb., rich in isoflavones and isoflavone glycosides, is widely used to treat osteogenic effects, pain, and other diseases. This study employed simple procedures based on preparative reversed-phase high-pressure liquid chromatography (prep-RP-HPLC) for large-scale isolation of isoflavones and isoflavone glycosides present in Dalbergia sissoo leaves (DSL). The seven compounds were isolated from the ethanolic extract by the preparative HPLC–PDA method, and their purity was > 95%. The authors carried out an in silico analysis to find possible anti-aging compounds. Isolated compounds biochanin-A-7-O-[β-Dapiofuranosyl-(1–5)-β-D-apiofuranosyl-(1–6)-β-D-glucopyranoside (DS2) and biochanin-A-7-O [β-D-apiofuranosyl-(1–6)-β-D-glycopyranoside (DS3) demonstrated docking scores of −10.466 and −9.430 with docking energies of -81.864 and -77.531 kcal/mol, respectively, to the Hyaluronidase enzyme. For the Collagenase enzyme, they showed docking scores of −10.734 and −10.777 with docking energies of −107.102 and −98.317 kcal/mol, respectively. Against the Tyrosinase enzyme, Compounds DS2 and DS3 had docking scores of −7.333 and −7.993 with docking energies of −59.933 and −84.825 kcal/mol, respectively. For the elastase enzyme, they exhibited docking scores of −9.840 and −7.993 with docking energies of −68.490 and −84.815 kcal/mol, respectively. This study found that the isolation and purification method is simple and produces neat chromatograms with good selectivity and reproducibility. At the same time, docking results revealed that the compounds exhibited anti-aging properties.

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Coronary artery disease (CAD) is a very common cardiovascular disease. Clinically, the content of low-density lipoprotein-cholesterol (LDL-C) is often used as a predictor of CAD. However, severe CAD has been observed in patients with normal level of LDL-C. In this study, the serum lipoproteins stained with Sudan Black B (SBB) were separated and characterized by using asymmetrical flow field-flow fractionation (AF4) coupled with ultraviolet visible (UV/Vis) detector (AF4-UV/Vis). The effects of SBB staining conditions and AF4 operation conditions on AF4 analysis of serum lipoproteins were systematically investigated. The membrane fouling was alleviated by adjusting SBB staining conditions, which enhances the repeatability and accuracy of AF4 analysis of serum lipoproteins. Moreover, the baseline separation of LDL and high-density lipoprotein (HDL) was obtained by AF4 under optimized operation conditions. The results showed that the LDL/HDL value of healthy people was lower than that of CAD patients. The results revealed that the combination of AF4-UV/Vis and SBB staining is a promising approach for the separation and characterization of serum lipoproteins, which is beneficial to screening potential predictors of CAD.

The purpose of this study was to develop and validate a robust, precise, and selective high-performance liquid chromatography (HPLC) method for the separation and determination of related impurities in fosaprepitant dimeglumine API. The chromatographic separation was performed on a Supersil ODS-2 column (250 × 4.6 mm, 5 µm) at a wavelength of 215 nm using a mixture of phosphate buffer (pH 2.15) and acetonitrile as the mobile phase in gradient elution mode. The validation results demonstrate that the method exhibits acceptable specificity, linearity, accuracy, precision, and robustness. The detection limits and quantitation limits ranged from 1.5 to 12.5 ng mL⁻¹ and from 3.0 to 37.5 ng mL⁻¹, respectively. A linear relationship was observed between the peak area and concentration of fosaprepitant and its eight related impurities with a correlation coefficient value of r² ≥ 0.999. The analysis of commercial fosaprepitant dimeglumine products revealed a significantly higher purity than expected, with all known impurities falling below specification limits. The new HPLC method has been successfully applied to analyze commercial bulk drug samples and is suitable for quality-control laboratories for both qualitative and quantitative assessment of eight related substances in the fosaprepitant dimeglumine API.

The objective of the present numerical investigation is to propose a microseparator specifically engineered for the separation of platelets from white blood cells (WBCs). This microfluidic device, which incorporates circular electrodes operating at a minimal voltage of 1.4 V, and a frequency of 100 kHz, is recommended for the targeted separation of platelets and WBCs utilizing dielectrophoresis (DEP) force. The utilization of a low-voltage level ensures the preservation of the viability of biological cells, a fundamental consideration in medical applications. Simulation results are presented to illustrate the electric potential, electric field, velocity, pressure, and DEP force profiles concerning two distinct particles. Through a comparative analysis employing the finite element method, we delineate the implications of modulating the inlet velocity field on the pressure exerted upon the particles. Subsequently, the impact of varying the fluid conductivity and input voltage on electrodes within the microchannel on particle separation was examined. It is anticipated that this comprehensive design is exceptionally conducive to the realization of DEP-based practical biochips for cell separation.

A rapid and efficient reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the simultaneous determination of six antiviral drugs: emtricitabine (EMT), entecavir (ENT), favipiravir (FAV), ganciclovir (GAN), valaciclovir (VAL), and valganciclovir (VLG). Chromatographic separation was achieved on an ExsilTM Mono 100 C18 column using a mobile phase of 50 mM phosphate buffer (pH 4): acetonitrile (90:10, v/v) at a flow rate of 0.5 mL/min. UV detection was performed at 215 nm. The method was validated according to ICH Q2(R2) guidelines, demonstrating excellent linearity (R² > 0.9938) across the concentration ranges of 1.0–150 μg/mL for EMT, ENT and VLG, and 5.0–200 μg/mL for FAV, GAN and VAL. The LOD and LOQ values ranged from 0.02 to 0.48 μg/mL and 0.05 to 1.45 μg/mL, respectively. Intra-day and inter-day precision, expressed as relative standard deviation (RSD), were less than 1.82%, while accuracy, expressed as relative error (RE), was within ± 1.34%. Recovery studies yielded values ranging from 98.12% to 101.60%, further confirming method accuracy. The method proved to be selective, robust, and suitable for the quantitative analysis of these antiviral drugs in pharmaceutical formulations, with results obtained for commercially available tablets demonstrating excellent agreement with labeled contents. Notably, stability studies revealed the susceptibility of EMT, ENT, and FAV to degradation under refrigerated storage, highlighting the need for timely analysis of these compounds. In addition, the greenness, blueness, and whiteness of the method were evaluated, and the developed method performs strongly across environmental (AGREE score: 0.79), practical (BAGI index: 85), and sustainability (whiteness value: 74.7) criteria, reinforcing its viability as a sustainable approach for antiviral analysis. This validated RP-HPLC method provides a reliable and efficient tool for the quality control of these essential antiviral medications.

The detection and quantification of genotoxic impurities, specifically nitrosamines, in pharmaceuticals have garnered high regulatory attention due to their potential carcinogenic effects. This study presents a comprehensive validation of a liquid chromatography with Atmospheric Pressure Chemical Ionization (APCI) Coupled with Triple Quardrapole Analyser (LC-MS/MS) method tailored for the determination of multiple nitrosamine impurities including N-nitrosodimethylamine (NDMA), N-nitroso methyl butyl amine (NMBA), N-nitrosodiethylamine (NDEA), N-nitroso diethyl isopropyl amine (NEIPA), N-nitrosodiisopropylamine (NDIPA), N-nitroso methyl ethyl amine (NMPA), N-nitroso propyl amine (NDPA), N-nitrosopiperidine (NPIP), N-nitrosopyrrolidine (NPYR), and N-nitroso butyl amine (NDBA) in telmisartan tablet formulations. The method was meticulously validated according to the International Council for Harmonisation (ICH) guidelines, focusing on critical parameters such as specificity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and filter compatibility. The specificity of the method was rigorously established, demonstrating unequivocal differentiation between nitrosamine impurities and potential interferences from excipients and active pharmaceutical ingredients (APIs). Recovery studies validated the method’s accuracy, yielding recoveries within the acceptable range of 70–120% across various concentration levels, confirming its reliability for routine analysis. Precision was assessed through the relative standard deviation (RSD) of multiple replicate analyses, with RSD values consistently below the ICH threshold of < 15%, underscoring the method’s reproducibility. Sensitivity assessments revealed exceptional LODs as low as 10.76 ppb and LOQs around 33.00 ppb for several nitrosamines, significantly exceeding current regulatory limits for genotoxic impurities. Evaluations of filter compatibility indicated that both 0.22 µm PVDF and 0.2 µm nylon filters are effective for sample preparation, ensuring the integrity of the analytes during the filtration process. Upon application of the validated method to commercial 40 mg telmisartan tablets, all targeted nitrosamines were undetected, affirming the method’s applicability in routine quality control settings. This work culminates in the establishment of a highly sensitive, specific, and robust LC–MS/MS methodology for the detection of nitrosamine impurities in telmisartan, addressing regulatory concerns while ensuring patient safety. The low detection thresholds provided by this method position it as an invaluable tool for pharmaceutical manufacturers and regulatory bodies, facilitating stringent monitoring and compliance with safety standards, ultimately enhancing the safety profile of medicinal products in the market.

The number of potentially abused substances in horse racing is very large and it is not easy to analyse the full range. To facilitate the analyses of substances of abuse, a method has been developed for 63 substances in horse urine using liquid chromatography–tandem mass spectrometry. The developed method has been validated according to the 2021/808/EC and AORC criteria. The horse urine samples were extracted after enzymatic hydrolysis via a C8-BCX SPE cartridge with an automated SPE and analyzed by LC–MS/MS. According to the validation study results, the within-laboratory reproducibility CV was no more than 13.9% and the average recoveries ranged from 90.71 to 117.94% for repeatability and reproducibility. The decision limits (CCα) for quantitative analysis and detection capabilities (CCβ) for qualitative screening were close to the targeted limit for each substance. The results of the present study showed that the method was able to perform quantitative analyses of 54 substances and screening analyses of 9 substances (total 63) in horse urine and that the results were valid and applicable. The validated method was successfully applied to five proficiency tests and three suspected samples.

The optimization of mobile phase composition in HPLC is crucial for achieving excellent chromatographic performance. Mobile phase additives are very often added to control retention, resolution, peak shape and efficiency. According to the Hofmeister series, additives are classified into chaotropic and kosmotropic agents. When ionizable compounds are analysed by hydrophilic interaction liquid chromatography (HILIC), additives can control the electrostatic interactions and affect the chromatographic parameters. In this study, citicoline, a neurotransmitter, was analysed under HILIC conditions using various additives. Due to the solubility limit in high organic content, the composition of the mobile phase was fixed at a 2/1 (V/V) acetonitrile/water ratio, and the salt concentration set to 25 mM. A total of 21 additives were tested, including short-chain organic acids (formic, acetic, propionic, trifluoroacetic and trichloroacetic acid), cations (lithium, sodium, potassium and ammonium) and anions (acetate, bromide, chloride, dihydrogen citrate, dihydrogen phosphate, nitrate, perchlorate and tetrafluoroborate). With additive-free mobile phases, weak retention of citicoline was observed, which can be explained by the small thickness of the water layer on the surface of the silica stationary phase and electrostatic repulsion between deprotonated silanols and negatively charged citicoline. However, the use of additives improves retention. Short-chain organic acids increased retention, but produce poor peak shape. Cations affected retention in the following order: ({{varvec{L}}{varvec{i}}}^{+}<{{varvec{N}}{varvec{H}}}_{4}^{+}<{{varvec{N}}{varvec{a}}}^{+}<{{varvec{K}}}^{+}), corresponding to the reversed Hofmeister series. The anions trend was: ({{varvec{C}}{varvec{H}}}_{3}{varvec{C}}{{varvec{O}}{varvec{O}}}^{-}<{{varvec{H}}}_{2}{{varvec{P}}{varvec{O}}}_{4}^{-}<{{varvec{B}}{varvec{r}}}^{-}<{{varvec{C}}{varvec{l}}}^{-}<{{varvec{H}}}_{2}{{varvec{C}}{varvec{i}}{varvec{t}}{varvec{r}}{varvec{a}}{varvec{t}}{varvec{e}}}^{-}<{{varvec{N}}{varvec{O}}}_{3}^{-}<{{varvec{C}}{varvec{l}}{varvec{O}}}_{4}^{-}<{{varvec{B}}{varvec{F}}}_{4}^{-}), which corresponds to the direct Hofmeister series, except for acetate and dihydrogen phosphate.

Oflox-TZ, Dto, and Ofnida syrup are well-known antimicrobial combination medications used to treat illnesses caused by parasites and bacteria. Environmentally sustainable model creation for antimicrobial compounds utilizing chemometric application, isosbestic point, and dual wavelength assisted by spectrophotometric and chromatographic analysis using ANOVA comparison with all developed methods. Deconvolution of the spectral overlaps and harmful use of organic solvents in spectrophotometric and chromatographic conditions with these combinations were performed using the partial least squares method, either with or without variable selection methods such as principal component regression. A good agreement was found when comparing the findings of the developed methods statistically to an ANOVA, indicating the efficacy of the suggested methodology. Calibration and validation sets comprising 24 and 12 samples, respectively, were carefully developed using partially factorial designs for the experiments at different dosages. The developed models were validated according to established International Council for Harmonisation (ICH) strategies. For the dual-wavelength approach, Beer’s plot confirmed linearity between 2 and 12 µg/mL for (OFL) and 5 and 30 µg/mL for Tinidazole (TZ) respectively. The mean percent recoveries were found to 101.0% and 102.0% for OFL and TZ. Chemometrics-assisted UV spectrophotometry, employing both partial least squares (PLS) and principal component regression (PCR) analysis models, yielded mean OFL recoveries of 102.3% (PLS) and 102.4% (PCR), and TZ recoveries of 102.6% (PLS) and 102.6% (PCR). Additionally, chromatographic model development using hydrotropic solutions yielded mean percentage recoveries of 100.2% and 100.6% for OFL and TZ, respectively, in commercial drug formulations. The study found that the proposed chemometric-assisted spectrophotometric and chromatographic methods could reliably determine OFL and TZ concentrations in both laboratory-prepared mixtures and pharmaceutical preparations, thereby proving them to be useful analytical instruments for quality control and in-process testing of different pharmaceutical drug preparations. This approach provides a significant outcome over the use of less polluted solvents, making it more precise and economical.

Graphical Abstract

Metal–organic frameworks (MOFs) have a wide range of applications in separation and analytical sciences due to their unique structures. MIL-100(Fe) was immobilized on the inner wall of the capillary column based on the immobilized cysteine (Cys)-triggered in situ growth (ICISG) strategy. By applying this column to capillary electrophoresis, a novel enantioselective separation system based on MIL-100(Fe) nanomaterial was established. By utilizing lactobionic acid (LA) as the chiral selector and optimizing the experimental conditions such as buffer pH, LA concentration and the methanol addition ratio, the CEC system demonstrated a significantly enhanced enantioseparation ability for six basic drugs. The modified capillary column was characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscope (EDS) and X-ray diffractometer. The experimental results showed that MIL-100(Fe) was successfully grown on the inner wall of the capillary column. In the present study, the repeatability of the coated column was investigated and the relative standard deviations (RSDs) of the resolution and the migration time for intra-day, inter-day and inter-column were within 8%, proving the good repeatability of the coated column.