A green sample preparation strategy for Cl and S determination in crude oil by ion chromatography.

Tiroler Bergkäse PDO is a traditional Austrian hard cheese from Tyrol, a product of great regional significance. This study aimed to describe Tiroler Bergkäse PDO by comparing it with Bergkäse without PDO from Tyrol and a Stilfser type cheese from South Tyrol. To account for variability, three cheese wheels from three production days were analyzed for each cheese. Multimethodological characterization included quantitative Polymerase Chain Reaction, Ion Exchange Chromatography, and Headspace-Solid Phase Microextraction/Gas Chromatography-Mass Spectrometry. The characterization Tiroler Bergkäse PDO should impart potentially unique features. Multivariate analysis of the bacterial composition, free amino acid content, and volatile fraction revealed differences between all cheeses (α=0.05). A triangle test confirmed significant differences, with more pronounced differences between the Bergkäse type cheeses and the Stilfser type cheese. The Stilfser type showed distinct differences in bacterial composition, amino acid content, and volatile profile, making it less similar to the Bergkäse type cheeses. Multivariate analysis also revealed differences between the PDO and non-PDO Bergkäse which is characterized by high levels of L. delbrueckii due to its starter culture, and a high free amino acid content from longer ripening, alongside elevated levels of hexanal and acetoin. In contrast, Bergkäse without PDO shows high levels of 2,3-butanediol and 2-nonanone, alongside high levels of L. mesenteroides, L. lactis subsp. lactis, and L. lactis subsp. cremoris. It was possible to distinguish between Tiroler Bergkäse PDO from non-PDO cheeses by microbial, amino acid, and volatile profiles and support the use of advanced methods to characterize regional foods.

Chemical structure and P-selectin inhibition of two linear and highly regular homofucans from the brown alga Fucus vesiculosus.

The mechanism and potential applications of per-aqueous liquid chromatography (PALC) using highly aqueous non toxic and environmentally friendly mobile phases were investigated using a number of polar stationary phases primarily manufactured for hydrophilic interaction chromatography. Stationary phases were probed with a range of simple acid, neutral and basic solutes of low MW. For charged solutes, ion exchange (IEX) was the dominant retention mechanism; hydrophobic effects and possibly direct adsorption onto the polar column surface also contribute. IEX is a rather neglected mechanism and deserves further study in analytical separations, due to favourable mobile phase properties. Peak shapes were good for adenosine mononucleotides (MW ∼500) despite predictions that poor peak shapes would result from multipoint interactions. Whether PALC should be regarded as a new technique or a combination of classical mechanisms is debated.

A novel cloud point extraction method has been developed for the simultaneous isolation of uranium and thorium from carbonate microsamples. This method offers an alternative to conventional ion-exchange chromatography for uranium and thorium purification prior to high-sensitivity determination by ICP-MS. For this, Triton X-114, cetyl trimethyl ammonium bromide (CTAB) and H 2 DEH[MDP] (P,P-di(2-ethylhexyl) methanediphosphonic acid) were used. Quantities of extraction reagents were first optimized to determine the threshold values allowing quantitative extraction of U and Th in the case of a 1 mg carbonate sample containing up to 2 μg g −1 of U and Th combined. Competitiveness was also investigated and the developed CPE system allowed a selective extraction of U and Th even in the simultaneous presence of several μg mL −1 of calcium and magnesium. Additionally, resolubilization of the surfactant rich phase (SRP) was investigated and reduced to 100 μL to ensure maximal analyte signals during analysis. Finally, phase separation temperature was identified as a key parameter controlling analyte extraction rates and 23 °C was determined as the optimal temperature to ensure systematic quantitative extraction of both elements. Samples were analyzed using manual micro-injection into the ICPMS. Under these conditions, the recovery of uranium and thorium was found to be within 98% and 105%, respectively. The signal reproducibility (peak integration) was measured at 3.4% and 6.9% (2xRSD, n = 5) for thorium and uranium, respectively. The developed method could thus be proposed for U/Th dating of speleothems from micro-samples, which could prove valuable in the context of cave studies subjected to stringent preservation requirements. • Development of a H 2 DEH[MDP]-based CPE system for U and Th quantitative co-extraction from aqueous sample in acidic conditions. • Extraction reagents quantities were optimized and decreased by 33% compared to initial conditions. • Extraction of U and Th remained quantitative, even in the presence of several μg.mL −1 of Ca and Mg. • No significant elemental and isotopic fractionation were observed. • Coacervate resolubilization volume successfully decreased from 5 mL to 100 μL which significantly increased analytes signals.

Strategies to assess PFAS emissions from a fluoropolymer manufacturing plant.

Analysis of nitrite in pharmaceutical excipients: A multi‑laboratory comparative study.

LC-MS/MS analysis of polar pesticides in mango: enantiomers, docking, and retention mechanisms.

Temperature-responsive ionic liquid hydrogel coating silica used for multi-mode chromatographic stationary phase.

The development of extracellular-vesicle-based therapeutics requires robust analytical assays and scalable downstream processing strategies to ensure product quality and reproducibility. In this study, we established an analytical toolbox comprising scattering and fluorescence mode nanoparticle tracking analysis, fluorescence-based flow cytometry, and multidetector analytical size-exclusion chromatography. Liposomes, selected for their biophysical similarity to EVs, were used as reference materials to optimize assay parameters, fluorescence labeling conditions, and dynamic range, minimizing artifacts such as photobleaching and masking effects. Using these optimized analytical tools, we established a scalable downstream processing (DSP) workflow for human bone marrow mesenchymal stromal cell-derived EVs (MSC-EVs), incorporating clarification, tangential flow filtration, ion exchange chromatography, buffer exchange, and sterile filtration. We first designed and optimized the DSP process at small scale using ion exchange chromatography (IEX). We integrated controls such as medium-alone control to ensure the cell-secreted nature of the final preparation. Using a stepwise elution strategy, IEX chromatography resulted in the elution of two cell-secreted populations. We then investigated the identities of these two IEX eluates using orthogonal analytical techniques. Transmission electron microscopy revealed that eluate 2 was enriched in EVs with a cup-shaped morphology, while eluate 1 contained nonvesicular extracellular particles (NVEPs). Eluate 2 also showed higher expression of positive markers such as CD81 and CD73 using Simple Western and expressed MSC-specific RNA markers compared with eluate 1. Proteomic and lipidomic analyses further validated the enrichment of EVs in eluate 2. Then, the analytical toolbox was utilized to monitor the DSP process for particle recovery and impurity removal throughout the process. Together, these results demonstrate that orthogonal analytics coupled to a scalable DSP yield reproducible MSC-EV preparations while depleting commonly co-isolated NVEPs. This practical framework advances process analytics of MSC-EV manufacturing and supports reporting of identity, purity, and function, aligned with existing guidelines in the field.

Plant-based serine protease inhibitors represent a promising class of bioactive compounds with potential therapeutic relevance. In this study, serine protease inhibitor-enriched peptide fractions were isolated from Zingiber officinale, Allium sativum, and Momordica charantia. Fractions were enriched using ammonium sulfate precipitation, followed by ion-exchange chromatography, and characterized using preliminary physicochemical approaches, including SDS-PAGE (≈ 1-15KDa), UV-visible spectroscopy, Fourier-transform infrared analysis, and amino acid profiling. The peptide-enriched fractions exhibited moderate antibacterial activity against Escherichia coli and Bacillus thurigiensis, with MIC values in the mg/ml range, consistent with partially purified natural fractions. Antifungal activity against Aspergillus niger was observed at approximately 4mg/mL. In a plant-based Tobacco Mosaic Virus (TMV) model using Nicotiana leaves, the peptide-enriched fractions reduced lesion development, indicating measurable antiviral activity. In this experimental system, the maximum inhibition ranged from approximately 58% to 86% depending on the assay format. Thrombolytic assays demonstrated moderate clot lysis (up to 42.95%) with low hemolytic activity under the tested conditions. Molecular docking suggested potential interactions between peptide motifs and serine protease targets, providing a basis for experimental evaluation. Consistent with this, enzyme inhibition assays demonstrated serine protease inhibitory activity, with IC50 values ranging from 0.15 nM (ASP fraction) to 24 µM (ZOP fraction). Kinetic analyses further revealed distinct modes of inhibition, including competitive, uncompetitive, and mixed mechanisms, depending on the fraction evaluated. As structural identity and purity were not confirmed using the mass spectrometry-based approaches, these findings should be interpreted as an early-stage functional assessment. Definitive structural characterization and further biological validation are necessary to clarify their mechanistic and translational relevance.

Sugars are one of the important chemical components in tobacco. They serve as key precursor substances for various aromatic compounds in tobacco. Furthermore， they also have a significant impact on the taste and burning characteristics of tobacco. Thus， obtaining accurate information on the composition and content of soluble sugars in tobacco can provide a scientific basis for quality assessment of tobacco leaves. Moreover， it offers critical data support for quality control and process optimization. Traditional techniques for soluble sugar analysis include continuous flow analysis， ion chromatography， gas chromatography， and liquid chromatography， etc. However， these methods still have limitations such as tedious sample pretreatment， poor detection sensitivity， and low analysis efficiency. In contrast， ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry （UPLC-Q-TOF-MS） is a highly effective analytical technology. It integrates the excellent separation capability of UPLC and the superior sensitivity of MS. This combination offers great potential for qualitative and quantitative analysis of target compounds. Nonetheless， the types of soluble sugars detectable in tobacco by UPLC-Q-TOF-MS remain limited. This defect restricts the comprehensive evaluation of sugar components in tobacco. Herein， a rapid and accurate analysis method was established for high-throughput screening and quantification of 26 soluble sugars in tobacco leaves. The tobacco leaf samples were ultrasonically extracted with 30 mL 40% acetonitrile aqueous solution at 120 W for 30 min. Soluble sugar extract solution was prepared using a Waters Sep-Pak C18 solid-phase extraction cartridge. With the help of self-built sugar library， the tobacco leaf samples were screened by UPLC-Q-TOF-MS. Then matrix-matched standard calibration curves were employed to accurately quantify the target analytes. The established method was verified. The 26 soluble sugars exhibited good linear relationships with correlation coefficients （R2） ranging from 0.999 1 to 0.999 9. The limits of quantification （LOQs） were in the range of 0.03-20 mg/L. The spiked recoveries ranged from 92.39% to 111.75%， and relative standard deviations （RSDs） were ≤4.65%. Finally， this method was applied to analyze 59 tobacco leaf samples from different origins， grades and years. Six soluble sugars including erythritol， fructose， sorbitol， glucose， sucrose and inositol were successfully identified. The content of each soluble sugar varied significantly among samples from different origins， grades， and years. Even among samples from the same origin， grade， and year， the soluble sugar contents showed certain fluctuations. This is speculated to be related to factors such as the growth environment， maturity， processing， and harvest time of the tobacco leaves. Among them， the contents of fructose and glucose were at relatively high levels in all tobacco leaf samples. The soluble sugar content from Heilongjiang was generally higher than that from Guizhou， Hunan， and other regions. Additionally， the overall soluble sugar content in samples from 2021 and 2022 was higher than that from 2020. Principal component analysis （PCA） and hierarchical cluster analysis （HCA） were conducted on tobacco leaf samples from different positions， respectively. These analyses demonstrated significant differences in soluble sugar contents among tobacco leaves from different positions. It confirmed that soluble sugars could serve as effective indicators for distinguishing positions of tobacco leaves. In summary， the established method enables the qualitative and quantitative detection of the 26 soluble sugars without relying on standard substances. Moreover， the method exhibits high throughput， simplicity， rapidity， and accuracy. Meanwhile， it is suitable for the qualitative and quantitative detection of soluble sugars in tobacco leaf samples. It provides robust technical support for in-depth research on tobacco chemical components and the digital formulation design of cigarette products.

This work developed a novel analytical method to detect short- and ultra-short chain perfluoroalkyl carboxylic acids (PFCAs) in freshwater samples by direct injection using ion chromatography mass spectrometry (IC-MS). Ultra-short chain PFCAs, including trifluoroacetic acid (TFA), are often present in aqueous environments at higher concentrations than longer chain PFCAs, however there are currently a limited number of methods that can analyze them. Detection limits ranged between 1.3 and 2.8 ng L-1 (ppt) of the PFCAs (C2-C6) analyzed and were comparable to those of other LC-MS and GC-MS methods. The precision of this method ranged from 0.4-7.6% for all the PFCAs (C2-C6). An advantage of this method is that small samples sizes under 1 mL can be used. This method was applied to real freshwater samples including tap water, precipitation, lake water, and river water. TFA was detectable in most of the samples with online pre-concentration and no other additional pretreatment sample preparation; however, method performance decreased in samples with high conductivity. A new unidentified isobaric interferent for TFA was present in most of the freshwater samples.

An automatic and low-maintenance chelator ion chromatography method for rare earth element determination in industrial processing streams.

Purification and characterization of rabbit polyclonal immunoglobulin G using DEAE ion-exchange chromatography and dynamic light scattering.

The rapid industrial emergence of perovskite photovoltaics (PV) highlights their potential to complement silicon PV in meeting the growing global solar demand. As deployment scales, closed-loop recycling of perovskite PV will be beneficial to conserve critical resources and mitigate environmental risks associated with lead. However, mixed-cation, mixed-halide perovskites-typical in record-efficiency devices-undergo systematic composition drift during device fabrication. Consequently, material recovered from end-of-life modules inherits these deviations, degrading cell performance if reused without adjustment. To overcome this fundamental bottleneck in circular manufacturing, we developed a comprehensive quantification framework to audit and restore perovskite composition. By combining nuclear magnetic resonance (NMR), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and ion chromatography (IC), we obtained full compositional fingerprints of the hybrid perovskite recovered from processed solar-cell stacks, allowing us to resolve their altered composition and restore the material to match the original precursor formulation. Composition restoration effectively closed the performance gap, yielding recycled perovskite cells with efficiencies comparable to pristine devices. A cost analysis demonstrates this approach can achieve a 69.1% cost reduction, while preserving supply-constrained elements like Cs and I. These results demonstrate a practical, compositionally informed pathway for the sustainable, closed-loop manufacturing of complex perovskite absorbers.

Extraction, purification and characterization of lipoxygenase from foxtail millet (Setaria italica).

Blood collection tubes are widely used medical devices. Inaccurate citrate anticoagulant concentration can influence the results of coagulation tests. The producer’s expertise and responsibility are considered the quality safeguards. However, the tubes undergo changes during their lifecycle, partly due to storage conditions, and the end user or a third party has no comprehensive insight. A methodology is necessary to reveal the tube’s inherent characteristics. We provide insight into the anionic–cationic composition and pH of anticoagulant solutions in commercial tubes using high-performance ion exchange chromatography on a purified water model, making the anticoagulant volume accuracy assessment possible through a direct dye-dilution method. The results revealed differences between the tubes of two producers, Greiner BIO-ONE (A and A(nr)) and BD (C). Tube C has the most accurate anticoagulant amount. Both brands contain buffered citrate. The method of buffer preparation is not a source of interferant for the spectrometric method of the tubes’ quality evaluation. Acetate, formate, chloride, nitrite, sulfate, oxalate, bromide, and nitrate impurities were determined in anticoagulant solutions, all in tube A and some in the others. Tubes C exhibit the highest contamination with cations.

Expression and functional analysis of high-stability hybrid human trypsin.

Aging processes at the anode–separator contact surface (“interface”) critically affect the lifetime and safety of lithium-ion batteries. Nevertheless, the role of the important fluorine–containing anode passivation layers (“solid electrolyte interphases”, SEI) under application-oriented conditions remains insufficiently understood. In this study, industrial lithium-ion cells with graphite anodes and NMC 811-based cathodes were subjected to long-term cycling and high charging rates. X-ray computed tomography (CT) combined with post-mortem scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), as well as ion exchange chromatography, Fourier transform infrared spectroscopy (FTIR), and depth-resolved X-ray photoelectron spectroscopy (XPS), was employed to investigate SEI composition as a function of cycling temperature and cycle number. The results demonstrate that cycling temperature has a significantly stronger impact on cell aging than the number of completed cycles. Elevated temperatures promote formation of fluorine containing phases within the SEI, in particular LiF, accompanied by very likely dendrite-induced blocking of electrolyte transport pathways at the anode–separator interface. Furthermore, the fraction of irreversible capacity associated with fluorine–containing SEI-compounds (LiF and Li x PO y F z ) was quantified, revealing a temperature-dependent contribution to interfacial degradation. These findings provide mechanistic insight into temperature-driven SEI evolution and highlight the critical role of LiF in aging processes of industrial lithium-ion batteries. • Cycling temperature has a stronger impact on aging than cycle number. • Elevated temperatures promote formation of fluorine-containing SEI. • Fluorine-containing SEI accumulates at the anode–separator interface. • Fluorine-containing SEI formation correlates with cumulative irreversible capacity rise. • Interfacial fluorine-containing SEI contributes to charge transport limitation and impedance growth.