The elucidation of the structures of individual lignin molecules in heterogeneous lignin isolates poses a challenge, underscoring the need for the development of robust analytical methods. Herein, we report the combined use of NMR and MALDI-TOF MSn as a facile approach for distinguishing and determining the detailed structures of individual oligomeric molecules in heterogeneous lignin mixtures. Supported by NMR, MALDI-TOF analysis of acetylated lignins provides precision by enabling the facile discernment of inter-unit linkages in lignin molecules. Furthermore, the progression of lignin linkages could be tracked through population studies, yielding a structural progression map that elucidates the chemical features of individual oligomers in milled wood lignins and synthetic lignins. By unmasking lignin’s molecular heterogeneity, this study marks an essential milestone in lignin analytics with possibility to advance the frontiers of molecular-level research in both fundamental and applied lignin studies.

Due to the presence of high content of oxygenated compounds (aldehydes, alcohols, carboxylic acids, esters, ethers, furfurals, ketones, lignin-derived compounds, phenols, and sugars), bio-oil has inferior oil properties compared to petroleum-derived oils. This creates numerous technological challenges in downstream separation processes. The present study outlines recent research trends on various separation strategies for upgrading crude biogenic pyrolysis oil for the production of valuable commodities. The present study mainly focuses on the various separation strategies, such as column chromatography, distillation, membrane filtration, crystallization, solvent extraction, electrosorption, and fractional condensation with respect to principles of operation, efficiency, economy and environmental concerns. Phase separation using solvent and adsorbent was found to be the best separation strategy compared to others due to lower capital investment and energy expenditure. However, there are various technological challenges with separation strategies for scale-up in industries. A comparative analysis of various separation strategies with the application of various bio-oil fractions from aqueous phases of bio-oil is summarized to understand the possible pathways for utilization in various industries. A brief section on technoeconomic analysis with existing pilot and semi-pilot pyrolysis plants is presented to understand the economic feasibility of pyrolysis and upgrading strategies. In the end, a circular economy perspective of pyrolysis-separation and its integration with a machine learning model, are briefly outlined.

Thermal depolymerization of lignocellulosic biomass at 400-600 oC in the absence of oxygen yields liquid, char, and gas. The presence of high oxygenates (40 wt.%) in the liquid fraction contributes to deleterious properties such as low heating value, high viscosity, corrosiveness, and low thermal stability. The present study investigates an upgrading strategy for crude biogenic pyrolysis oil using various adsorbents (calcium hydroxide, red mud, bentonite, dolomite, used silica, and new silica) with petroleum ether as a diluent. The textural and microstructural features of the adsorbents are analysed using various characterization techniques - a scanning electron microscopy (SEM) and a Brunauer–Emmett–Teller (BET) specific surface area analyser. The objective of the study was to induce a separation of soluble and insoluble phases in petroleum ether (upper homogeneous fraction and lower non-homogeneous fraction with adsorbents) using various cheap adsorbents, and to find the best adsorbent for the refining process. The original crude oil and the refined oil from the upgradation strategy were extensively characterized using multiple analytical techniques to understand the chemical, thermal, and stability characteristics. The results showed that calcium hydroxide is more effective in the removal of oxygenates in comparison with other adsorbents due to variations in surface area.

The upgrading of crude biogenic pyrolysis oil (CO) was carried out using a simple scalable, inexpensive upgrading strategy based on the use of various adsorbents. The upgraded oil and the efficiency of the process were extensively characterized using various analytical techniques. The preliminary objective of the study was to identify the best adsorbent for refining CO. The adsorbents were characterized using scanning electron microscopy (SEM) and a Micromeritics 3Flex Instrument to determine the morphology and surface area of the adsorbents used. Crude and upgraded oil were extensively characterized to understand chemical composition, stability, and thermal properties. The importance of the study is to remove oxygenated compounds in CO using industrial waste adsorbents and solvent. The present upgrading strategy separates CO into an upper homogeneous soluble phase in petroleum ether and a lower non-homogeneous insoluble phase in petroleum ether. Oxygenates are reduced from 40.13 wt.% to 0.14 wt.% with the use of calcium hydroxide as an adsorbent and petroleum ether as a solvent. Finally, a discussion on the overview of the upgradation strategy is briefly summarized at the end of the manuscript

Glycosylation plays a critical role in modulating protein structure, stability, and binding properties, yet comprehensive tools to systematically characterize these effects are scarce. Here, we integrated multiple mass spectrometry (MS) techniques, including high-resolution nanoelectrospray ionization MS (nESI-MS), cross-linking matrix-assisted laser desorption/ionization time-of-flight MS (XL-MALDI-MS), native MS, ion mobility mass spectrometry (IM-MS), together with collision-induced unfolding and a temperature-controlled nESI source to comprehensively investigate glycosylation-dependent changes in protein structural and functional properties. Applying this integrated platform to human IgG Fc, we uncovered how glycosylation alterations in hospitalized COVID-19 patients impact Fc conformation, stability, and receptor binding. nESI-MS profiling revealed a loss of core fucosylation, galactosylation, and sialylation in patient samples. These changes in glycosylation, particularly the loss of fucosylation (afucosylation), correlate with enhanced FcγRIIIa binding, a more open conformation, and reduced stability. These findings highlight glycosylation as a key factor in immune dysregulation during severe COVID-19, and demonstrate the power of integrating multiple MS techniques to uncover the structural and functional consequences of glycan variation. This integrated MS platform is broadly applicable to other glycoprotein systems, including quality control in glycoengineering and research on infectious diseases.

Polyethylene terephthalate (PET) is commonly used in beverage packaging and can be recycled to reduce plastic pollution, raising concerns regarding non-intentionally added substances (NIAS). Here, two organic NIAS, acetaldehyde and benzene, and metal elements have been examined in PET materials. Elemental analysis revealed that higher recycled content in PET correlated with increased contaminant levels. Moreover, elevated acetaldehyde and benzene concentrations were noticed. PET degradation, intentional addition, and unknown sources complicate the analysis of the effects of the production, recycling, and storage on the introduction, formation, or migration of NIAS in PET materials. Benzene and acetaldehyde could migrate into beverages or the environment during storage. The migration of these two volatile substances was therefore quantified. Despite their presence in all PET materials, the low concentrations of acetaldehyde and benzene detected alleviate potential health concerns. This research contributes to the understanding of how recycling and recycled content impact the presence of NIAS in PET, offering insights for optimizing recycling practices and sustaining the role of PET in environmentally responsible beverage packaging.

Glycosylation is the most common protein post-translational modification, affecting protein properties and functions. Abnormal variations in glycosylation are associated with diseases, e.g., coronavirus disease COVID-19. Matrix-assisted laser desorption/ionization mass spectrometry has been widely utilized for studying protein glycosylation, after proper purification of glycopeptides or glycans using hydrophilic interaction liquid chromatography (HILIC) or laboratory-synthesized hydrophilic materials. Here, glass wool tips were developed to enrich immunoglobulin G glycopeptides and applied in the analysis of COVID-19 patient samples as a proof-of-concept. A significant decrease in galactosylation was detected in the COVID-19 patient plasma sample compared to the reference sample. The tips developed in this work provided a cheap and simple enrichment alternative to commercial HILIC tips for studying protein glycosylation.

Capillary electrophoresis is a powerful separation technique for analysis of proteins and peptides, with benefits like low consumption of reagents, solvents and sample. The separation efficiency and resolution can be deteriorated by adsorption of analytes to the inner capillary wall, though. Many methods to circumvent this obstacle have been reported, including background electrolyte addition of surfactants that aggregate as protective coatings at the wall. In this work, anionic suberin surfactant was used together with the cationic surfactant cetyltrimethylammonium bromide (CTAB) for analysis of trypsin digested lysozyme as a model sample. Suberin fatty acids were extracted from birch bark, which is a side-stream product originating from pulp and paper waste streams. Different adjustments of the solvent extraction protocol, and the method to neutralize the suberin fatty acids to obtain surface active sodium salts were evaluated regarding number of peaks observed, separation repeatability, and analysis time. The influence of background electrolyte pH was also studied. The potential of the surface-active sodium salts of suberin fatty acids as an additive enhancer in combination with CTAB is illustrated by excellent repeatability, especially at lower pH values. The number of peaks observed was also higher at lower pH, while the analysis time was shorter.

RationaleChemical mass shifts in quadrupolar ion traps have been studied previously but only for a limited number of analytes and mass ranges. Here, mass shifts of cluster ions, commonly used as calibrants, and other analytes are qualitatively evaluated on the Bruker amaZon spherical ion trap (QIT) and the Finnigan LXQ linear ion trap (LIT). To extend the mass range from previous experiments m/z up to 4000 are investigated. MethodsChemical mass shifts of CsI, Y(HCOO)(3), and NaCF3COO cluster ions, CF3COO-, Na+, and Cs+ adduct ions, protonated commercial calibration solutions and peptides, and deprotonated peptides were investigated on the Bruker amaZon speed QIT and some of these were also investigated on the Finnigan LXQ LIT. ResultsOn both instruments, peak distortions and mass shifts toward lower m/z became apparent as m/z approached 1000. To some extent, the issues were more severe at slower scans. Peak distortions included loss of resolution, tailing, or fronting and were different between the amaZon QIT and the LXQ LIT. The noncluster and nonadduct ions analyzed showed no obvious mass shifts or peak distortions under the same analysis conditions. ConclusionsAs expected, the ion traps investigated here showed mass shift and peak distortion issues, and such issues persisted at m/z up to 4000 on both instruments. Peak distortions were different between the amaZon QIT and the LXQ LIT, and were not always visible despite mass shifts. Both mass shifts and peak distortions make cluster ions and some adduct ions unsuitable for ion trap calibration.

The understanding of analytical chemistry and its application in different areas of life science is something that should be encouraged for students studying chemistry, and also something that appeals to many students. Life science includes a vast variety of areas, out of which some are more easily approached in student projects. The chemical communication between organisms, such as plants, as described in chemical ecology is one example. It is therefore beneficial to offer students inquiry-based project work that allows them to explore, and gain a deeper understanding of, this discipline within the grand context that is chemistry. Hence, the present work describes the application of analytical chemistry using gas chromatography-mass spectrometry, including sample preparation for the study of chemical inhibitory (allelopathic) properties of compounds found in the plant Aegopodium podagraria. The questions posed to the students performing this project work were "What compounds can be found in the extracts of the plant?", "Are the extracts allelopathic?", and "Can you determine which compounds contribute to the possible allelopathic properties?". The reported results indicate that the extracts might have allelopathic properties and showed that the extracts contained compounds such as alpha-pinene and beta-caryophyllene. The identified terpenes were shown to have minor allelopathic properties by themselves but displayed an impact on the germination of seeds and length of the sprouts when applied as a blend. This project, and its results, proposes a framework for investigation of other plants and can be adapted to suit students at different academic levels.