Mass Spectrometric Techniques Research Articles

DNA Adductomics: A Narrative Review of Its Development, Applications, and Future

DNA adductomics is the global study of all DNA adducts and was first proposed in 2006 by the Matsuda group. Its development has been greatly credited to the advances in mass spectrometric techniques, particularly tandem and multiple-stage mass spectrometry. In fact, liquid chromatography-mass spectrometry (LC-MS)-based methods are virtually the sole technique with practicality for DNA adductomic studies to date. At present, DNA adductomics is primarily used as a tool to search for DNA adducts, known and unknown, providing evidence for exposure to exogenous genotoxins and/or for the molecular mechanisms of their genotoxicity. Some DNA adducts discovered in this way have the potential to predict cancer risks and/or to be associated with adverse health outcomes. DNA adductomics has been successfully used to identify and determine exogenous carcinogens that may contribute to the etiology of certain cancers, including bacterial genotoxins and an N-nitrosamine. Also using the DNA adductomic approach, multiple DNA adducts have been observed to show age dependence and may serve as aging biomarkers. These achievements highlight the capability and power of DNA adductomics in the studies of medicine, biological science, and environmental science. Nonetheless, DNA adductomics is still in its infancy, and great advances are expected in the future.

Rapid detection of ingested acetaminophen on face mask by ambient ionization tandem mass spectrometry

BackgroundA regular face mask is comprised of three layers for resisting moisture, filtration, and absorbing oral fluid, respectively. Since the polymers with different polarities are used to make the layers, a face mask can be used as a sampling tool to retain polar or non-polar chemical and biochemical substances in the exhaled breath. In this study, thermal desorption-electrospray ionization tandem mass spectrometry (TD-ESI/MS/MS), an ambient ionization mass spectrometric technique, was used to detect trace acetaminophen that were exhaled and retained on the surface of different layers in a face mask. ResultsWith probe sampling combined with TD-ESI/MS/MS, the acetaminophen ion signal can be detected at the mouth/nostril region of the face mask after taking the acetaminophen tablet. The experimental results were similar to previous studies for the detection of acetaminophen in blood over time using LC/MS/MS. In addition, the intensities of acetaminophen on different layers of the face mask could reveal the differing distributions of exhaled acetaminophen on each layer. To explore the distribution of acetaminophen on the face mask surface, multiple probes were used to collect samples from different locations of the face mask for analysis. The molecular mapping of acetaminophen on the face mask was rendered by scaling the analyte ion signal intensity based on a temperature color gradient. The cartography showed a higher acetaminophen ion signal distribution on the mouth and nostril regions than in other areas of the face mask. SignificanceOwing to the advantages of a simple, sensitive, and non-invasive sampling approach, drug monitoring could be potentially performed to provide useful information for anti-drug of precision medicine in the future.

Treatment of antibiotics in mariculture wastewater via phosphate-doped porous coralline carbon nitride/porous mullite honeycomb sunlight-driven photocatalytic system: Morphological control, long-term and continuous flow application

Herein, this study describes a promising sunlight-driven photocatalytic system designed for the elimination of antibiotics (e.g., fluoroquinolones and sulfonamides) in real maricultural wastewater. Phosphate-doped porous coralline carbon nitride (P-CCN), synthesized by controlling morphology from two-dimensional block CN, was immobilized onto porous mullite honeycomb to construct a practical and molding photocatalytic system (P-CCN/PMH). By leveraging its microscopic porous coral structure, P-CCN displayed an augmentation in surface-active sites and a notable inner light refraction effect. This enhancement contributed to the high-efficiency performance of P-CCN/PMH system, producing 8.232 mM·h−1·g−1 H2O2 under sunlight, which was 7.21-fold higher than before modification; and its degradation rate constant to enrofloxacin (0.263 min−1) was 39.31-fold higher. The P-CCN/PMH system demonstrated superior capability in terms of adaptability to a wide concentration range, acid-alkali conditions, mineralization, carbon reduction, and challenging ionic surroundings or water matrices. Crucial superoxide radicals have been confirmed through mass-spectrometric technique and theoretical calculations, leading to ring-opening effects. Long-term and continuous-flow experiments were deeply carried out, validating the commendable competence of the P-CCN/PMH photocatalytic system in simulated wastewater treatment scenarios. Ultimately, the aggregate results highlight valuable insights into coralline materials synthesis and modular catalyst construction, presenting potential for addressing challenges related to environmental antibiotics pollution.

Transcriptomics and metabolomics analyses of graphene oxide toxicity on porcine alveolar macrophages

Graphene oxide (GO) is a type of nanomaterial widely used in tissue engineering, photocatalysis, and biomedicine. GO has been found to produce adverse effects on a broad range of cells and tissues. However, the molecular mechanisms underlying GO toxicity still remain to be explored. In this study, using porcine alveolar macrophages as a study model, we explored the toxic effects of GO and performed genome-wide detection of genes and metabolites associated with GO exposure using RNA-seq and liquid chromatograph mass spectrometer techniques. GO exposure significantly inhibited cell viability and induced apoptosis and oxidative stress in porcine alveolar macrophages. Further, GO exposure promoted cellular inflammation by upregulating the expression of pro-inflammatory cytokines (IL-6, IL-8, and IL-12). Transcriptomic analysis of GO-exposed cells revealed 424 differentially expressed genes. Functional enrichment analysis showed that the differentially expressed genes were significantly enriched in the pathways of Ribosome and oxidative phosphorylation (OXPHOS). In addition, metabolic analysis identified 203 differential metabolites, and these metabolites were significantly enriched in biosynthesis of cofactors, purine metabolism, and nucleotide metabolism. Integrative analyses of transcriptome and metabolome showed that OXPHOS was the most significantly enriched pathway and the involved genes were downregulated. This study revealed the toxic effects of GO on porcine alveolar macrophages and provided global insights to the metabolomic and transcriptomic alterations related to GO exposure. The results contributed to our understanding of the molecular mechanism of GO, and may further promote the detection of biomarkers for the prediction and control of GO toxicity.

Degradation of the neonicotinoid insecticide imidacloprid by ozonation and the E-peroxone process: Mechanisms, transformation products, and toxicity

In this study, degradation of the neonicotinoid insecticide imidacloprid (IMI) by ozonation and the E-peroxone process was investigated. Results show that IMI is an O3-refractory compound with second-order rate constants for the reaction with O3 and •OH (kO3,IMI and k•OH,IMI) being 3.9 and 3.95 × 109 M−1 s−1 at pH 7, respectively. Due to its low O3 reactivity, IMI was only abated by < 20 % in a selected groundwater during ozonation with typical ozone doses applied in water treatment (1–5 mg/L). In comparison, the E-peroxone process considerably enhanced IMI removal efficiency to > 80 % under similar reaction conditions. During both ozonation and the E-peroxone process, IMI was mainly abated by •OH oxidation. The reaction mechanism of IMI with •OH was investigated with quantum computations, which show that H-abstraction at H23 site was the most favorable pathway. Sixteen transformation products (TPs) generated from IMI degradation were identified using various chromatographic and mass-spectrometric techniques. The acute and chronic toxicities of IMI and its TPs to different aquatic organisms were evaluated with Microtox bioassay and the ECOSAR program, which indicate that some TPs (e.g., TP2–TP5 and TP7–TP9) are even more toxic than IMI to aquatic organisms (e.g., daphnia). The results of this study suggest that IMI along with its TPs should be sufficiently abated during water treatment, and the E-peroxone process provides an efficient option to upgrade conventional ozonation for enhanced IMI abatement.

Composition and Sources of Organic Aerosol in Two Megacities in Western China Using Complementary Mass Spectrometric and Statistical Techniques.

Over 300 daily PM2.5 filter samples were collected in two western Chinese megacities, Xi'an and Chongqing, from October 2019 to May 2020. Their aqueous extracts were nebulized simultaneously to an aerosol mass spectrometer (AMS) and a recently developed extractive electrospray ionization (EESI) mass spectrometer, for bulk and near-molecular organic aerosol (OA) composition, respectively. Carbonate was quantified using EESI and a total organic carbon analyzer to separate inorganic carbon from dust. Via isotopically-labelled internal standards and positive matrix factorization, seven water-soluble sources were quantified separately using the AMS- and EESI-based analyses, with consistent types, concentrations, and correlations. These include dust, solid fuel combustion (SFC)-related, nitrogen- (and sulfur-) containing, summer/winter oxygenated OAs, and a cigarette-related OA only in EESI. When accounting for water-solubility, SFC-related OAs were the largest (53%) sources in Chongqing, while dust (consisting of 77% OA and 23% carbonates) was the largest (30%) source in Xi'an. Overall, this study presents one of the first times that complementary mass spectrometric techniques independently resolved consistent OA sources-with added chemical information-over multiple seasons and locations of complex pollution. The methods and quantified sources are essential for subsequent chemical, modelling, and health studies, and policy making for air pollution mitigation.

Obscured Contribution of Oxygenated Intermediate-Volatility Organic Compounds to Secondary Organic Aerosol Formation from Gasoline Vehicle Emissions.

Secondary organic aerosol (SOA) formation from gasoline vehicles spanning a wide range of emission types was investigated using an oxidation flow reactor (OFR) by conducting chassis dynamometer tests. Aided by advanced mass spectrometric techniques, SOA precursors, including volatile organic compounds (VOCs) and intermediate/semivolatile organic compounds (I/SVOCs), were comprehensively characterized. The reconstructed SOA produced from the speciated VOCs and I/SVOCs can explain 69% of the SOA measured downstream of an OFR upon 0.5-3 days' OH exposure. While VOCs can only explain 10% of total SOA production, the contribution from I/SVOCs is 59%, with oxygenated I/SVOCs (O-I/SVOCs) taking up 20% of that contribution. O-I/SVOCs (e.g., benzylic or aliphatic aldehydes and ketones), as an obscured source, account for 16% of total nonmethane organic gas (NMOG) emission. More importantly, with the improvement in emission standards, the NMOG is effectively mitigated by 35% from China 4 to China 6, which is predominantly attributed to the decrease of VOCs. Real-time measurements of different NMOG components as well as SOA production further reveal that the current emission control measures, such as advances in engine and three-way catalytic converter (TWC) techniques, are effective in reducing the "light" SOA precursors (i.e., single-ring aromatics) but not for the I/SVOC emissions. Our results also highlight greater effects of O-I/SVOCs to SOA formation than previously observed and the urgent need for further investigation into their origins, i.e., incomplete combustion, lubricating oil, etc., which requires improvements in real-time molecular-level characterization of I/SVOC molecules and in turn will benefit the future design of control measures.

Generation of anti-SN38 antibody for loading efficacy and therapeutic monitoring of SN38-containing therapeutics

SN38, one of the most potent anti-tumor analogues of the camptothecins (CPTs), has limitations in its direct formulation as an anticancer agent due to its super toxicity and poor solubility in water and pharmaceutically approved solvents. However, it has garnered significant scientific interest as a payload in conjugated nanomedicine platforms (e.g., SN-38lip, NK012, SNB-101, and ADCs) to enhance their effectiveness and safety. The development of these platforms necessitates a convenient quantitative determination of SN38 in preclinical and clinical studies, a need that our study directly addresses, offering a practical solution to a pressing problem in cancer research and drug development. This study details the meticulous process of generating poly and monoclonal antibodies (pAb and mAb) against SN38 and their application to measure the SN38 in naked and conjugated forms of SN38-conjugated ADCs. For this purpose, two haptens of SN38 were synthesized by introducing the glycine or 4-amino-4-oxobutanyol(glycine) moiety as a conjugation functional group of the SN38. IR, NMR and mass spectrometric techniques confirmed the chemical modifications of the haptens. The haptens were then conjugated to each bovine serum albumin (BSA) and keyhole limpet hemocyanin (KLH) protein. The SN38-KLH conjugates were meticulously examined for immunization and generation of pAb and mAb. The immunization efficiency, reactivity, binding affinity, specificity, and cross-reactivity of purified pAb and mAb against Irinotecan, a model for the emergence of an SN38 derivative in clinical settings, were evaluated using ELISA and western blotting (WB) techniques. Conjugation efficiency of the SN38 to the KLH was increased using 4-amino-4-oxobutanyol(glycine) moiety, as its immunization efficacy was more to generate pAb. Furthermore, only this hapten could immunized mice to generate mAb recognizing SN38 with nanomolar equilibrium affinity. Our recent findings strongly support the notion that the generated pAb employed in developing an ELISA effectively ascertains the presence of SN38 in SN38-conjugated ADC, with a test midpoint EC50 of 2.5 μg/mL.Our study's unique contribution to the field lies in the development of specific antibodies against SN38 for measuring it on ADC, a feat that has not been achieved before. These immunoassays can be readily applied to detect other SN38-conjugate therapeutic platforms, thereby enhancing their clinical knowledge translation. The affinity of both pAb and mAb also meets the acceptance criteria for quantifying SN38 in fluidic material, as well as in Therapeutic drug monitoring (TDM) studies, a crucial aspect of personalized medicine. The potential applications of the anti-SN38 antibodies extend to reducing SN38-induced systemic toxicity through an inverse targeting strategy, a novel approach that piques further interest in our findings.

Marine Bacillus haynesii chitinase: Purification, characterization and antifungal potential for sustainable chitin bioconversion

The development of chitinase tailored for the bioconversion of chitin to chitin oligosaccharides has attracted significant attention due to its potential to alleviate environmental pollution associated with chemical conversion processes. In this present investigation, we purified extracellular chitinase derived from marine Bacillus haynesii to homogeneity and subsequently characterized it. The molecular weight of BhChi was approximately 35 kDa. BhChi displayed its peak catalytic activity at pH 6.0, with an optimal temperature of 37 °C. It exhibited stability across a pH range of 6.0–9.0. In addition, BhChi showed activation in the presence of Mn2+ with the improved activity of 105 U mL−1. Ca2+ and Fe2+ metal ions did not have any significant impact on enzyme activity. Under the optimized enzymatic conditions, there was a notable enhancement in catalytic activity on colloidal chitin with Km of 0.01 mg mL−1 and Vmax of 5.75 mmol min−1. Kcat and catalytic efficiency were measured at 1.91 s−1 and 191 mL mg−1 s−1, respectively. The product profiling of BhChi using thin layer chromatography and Mass spectrometric techniques hinted an exochitinase mode of action with chitobiose and N-Acetyl glucosamine as the products. This study represents the first report on an exochitinase from Bacillus haynesii. Furthermore, the chitinase showcased promising antifungal properties against key pathogens, Fusarium oxysporum and Penicillium chrysogenum, reinforcing its potential as a potent biocontrol agent.

Pyrene based AIE-active probe for selective detection of picric acid through the inner filter effect channel in aqueous medium

The development of pyrene derivatives possessing the AIE feature have emerged as an intriguing area of research with potential applications in several domains. In the present study, we designed and developed an AIE active pyrene derivative for picric acid sensing in an aqueous medium. The design based on a single step condensation reaction and the product has been meticulously characterized by using NMR and Mass spectrometric techniques. In comparison to pristine pyrene, the synthesized pyrene derivative has a lower bandgap energy as a result of the intramolecular charge transfer between pyrene and 4-(methylthio)-2-oxo-2H-pyran-3-carbonitrile. The synthesized probe demonstrates a moderate level of fluorescence when dissolved in a solution, and it has exhibited a remarkable emission caused by aggregation at higher water percentages. The aggregates were meticulously characterized by DLS, SEM and TEM measurements. The spherically shaped aggregates have shown enhanced fluorescence quantum yield and lifetime, rendering them a more suitable option for sensor applications. The aggregates were effectively employed as a fluorescent probe for the detection of picric acid in an aqueous medium. The probe exhibited a notable level of selectivity and sensitivity towards picric acid, as evidenced by its low detection limit of 4.47 nM. Moreover, the quenching mechanism was ascribed to the inner filter effect, providing supporting evidence from both experimental and mathematical calculations. The findings indicate that the probe has potential as a feasible choice for a picric acid sensor.

Stepping-up accurate quantification of chlorinated paraffins: Successful certification of the first matrix reference material

BackgroundChlorinated paraffins (CPs) are industrial chemicals categorised as persistent organic pollutants because of their toxicity, persistency and tendency to long-range transport, bioaccumulation and biomagnification. Despite having been the subject of environmental attention for decades, analytical methods for CPs still struggle reaching a sufficient degree of accuracy. Among the issues negatively impacting the quantification of CPs, the unavailability of well-characterised standards, both as pure substances and as matrix (certified) reference materials (CRMs), has played a major role. The focus of this study was to provide a matrix CRM as quality control tool to improve the comparability of CPs measurement results. ResultsWe present the process of certification of ERM®-CE100, the first fish reference material assigned with certified values for the mass fraction of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively). The certification was performed in accordance with ISO 17034:2016 and ISO Guide 35:2017, with the value assignment step carried out via an intercomparison of laboratories of demonstrated competence in CPs analysis and applying procedures based on different analytical principles. After confirmation of the homogeneity and stability of the CRM, two certified values were assigned for SCCPs, depending on the calibrants used: 31 ± 9 μg kg−1 and 23 ± 7 μg kg−1. The MCCPs certified value was established as 44 ± 17 μg kg−1. All assigned values are relative to wet weight in the CRM that was produced as a fish paste to enhance similarity to routine biota samples. Significance and noveltyThe fish tissue ERM-CE100 is the first matrix CRM commercially available for the analysis of CPs, enabling analytical laboratories to improve the accuracy and the metrological traceability of their measurements. The certified CPs values are based on results obtained by both gas and liquid chromatography coupled with various mass spectrometric techniques, offering thus a broad validity to laboratories employing different analytical methods and equipment.

Improving the therapeutic window of anticancer agents by β-cyclodextrin encapsulation: Experimental and theoretical insights

3-Nitro-2H-chromene derivatives exhibit promising anticancer activities, but their clinical translation is hindered by poor aqueous solubility. Herein, we report a cyclodextrin complexation strategy to improve the solubility and therapeutic efficacy of 8-methoxy-2-(4-methoxy phenyl)-3-nitro-2H-chromene (MNC), a potent anticancer agent. Solid inclusion complexes of MNC: β-cyclodextrin (β-CD) were synthesized by co-precipitation and kneading methods, and comprehensively characterized using UV–vis, Fluorescence, Fourier Transform Infrared (FT-IR), Differential scanning calorimetry (DSC), X-ray diffraction (XRD), Scanning electron microscope (SEM), 1H NMR, and mass spectrometric techniques. A 1:1 host–guest stoichiometry was verified by phase solubility and UV–Vis spectroscopic studies. β-CD complexation remarkably enhanced the aqueous solubility of hydrophobic MNC. Cytotoxicity evaluation against different human cancer cell lines such as breast cancer (MCF-7, MDA-MB-231), lung cancer (A549), and liver cancer (HepG2) demonstrated superior anticancer activity of the co-precipitated MNC: β-CD complex compared to free MNC and the chemotherapeutic 5-fluorouracil. Although the host–guest interaction energy obtained from molecular docking was modest (−5.1 kcal/mol), it facilitated effective MNC encapsulation and delivery by β-CD. Density functional theory (DFT) calculations provided further insights into the inclusion phenomenon. This cyclodextrin complexation approach paves the way for developing an effective MNC formulation with improved bioavailability and anticancer therapeutic efficacy.

GPR39-mediated ERK1/2 signaling reduces permethrin-induced proliferation of estrogen receptor α-negative cells

Certain insecticides are known to have estrogenic effects by activating estrogen receptors through genomic transcription. This has led researchers to associate specific insecticide use with an increased breast cancer risk. However, it is unclear if estrogen receptor-dependent pathways are the only way in which these compounds induce carcinogenic effects. The objective of this study was to determine the impact of the pyrethroid insecticide permethrin on the growth of estrogen receptor negative breast cancer cells MDA-MB-231. Using tandem mass spectrometric techniques, the effect of permethrin on cellular protein expression was investigated, and gene ontology and pathway function enrichment analyses were performed on the deregulated proteins. Finally, molecular docking simulations of permethrin with the candidate target protein was performed and the functionality of the protein was confirmed through gene knockdown experiments. Our findings demonstrate that exposure to 10–40 μM permethrin for 48 h enhanced cell proliferation and cell cycle progression in MDA-MB-231. We observed deregulated expression in 83 upregulated proteins and 34 downregulated proteins due to permethrin exposure. These deregulated proteins are primarily linked to transmembrane signaling and chemical carcinogenesis. Molecular docking simulations revealed that the overexpressed transmembrane signaling protein, G protein-coupled receptor 39 (GPR39), has the potential to bind to permethrin. Knockdown of GPR39 partially impeded permethrin-induced cellular proliferation and altered the expression of proliferation marker protein PCNA and cell cycle-associated protein cyclin D1 via the ERK1/2 signaling pathway. These findings offer novel evidence for permethrin as an environmental breast cancer risk factor, displaying its potential to impact breast cancer cell proliferation via an estrogen receptor-independent pathway.

ANALYTICAL TECHNIQUES IN PHARMACEUTICAL POLLUTION OF THE WORLD’S RIVERS; A REVIEW

Recent reports of new pollution issues brought on by the presence of medications in the aquatic environment have sparked a great deal of interest in studies aiming at analyzing and mitigating the associated environmental risks, as well as the extent of this contamination. The main sources of pharmaceutical contaminants in natural lakes and rivers include clinic sewage, pharmaceutical production wastewater, and sewage from residences that have been contaminated by drug users' excretions. In evaluating the health of rivers, pharmaceutical pollutants have been identified as one of the emerging pollutants. The previous studies showed that the contaminants in pharmaceuticals that are widely used are non-steroidal anti-inflammatory drugs, antibiotics, antiretrovirals, and anticancer drugs. Additionally, this review demonstrated the use of analytical techniques to examine these contaminants in various kinds of River water. Due to their extremely low concentrations in the aqueous environment (about in the range of ng/L to g/L), it is necessary to apply a technique for highly sensitive and selective multicomponent simultaneous analysis to identify and quantify these products. This analytical technique provides a flexible and reliable means to identify and evaluate pharmaceutical contaminants in river water samples by combining solid phase extraction and hyphenated mass spectrometric techniques. SPE-LC/MS/MS is the main method for estimating the level of pollution. For citation: Jamur Jasim. M.S. Analytical techniques in pharmaceutical pollution of the world’s rivers; a review. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 5. P. 6-16. DOI: 10.6060/ivkkt.20246705.7017.

Phytochemical screening, gas chromatograph/mass spectrometer (GCMS) analysis and molecular toxicological potential of Hunteria umbellata aqueous fruit extract against Staphylococcus aureus in accessory gene regulators (AGRs)

BackgroundFruits of Hunteria umbellata (HU) have been utilized in folk medicine as potent against Staphylococcus aureus (SA) infections, particularly skin and nasal related conditions. However, there is scarcity of literature concerning toxicological evaluation of graded doses of HU fruit, especially at molecular level, specifically targeting the accessory gene regulator (AGR) system to prevent abuse of doses in the treatment of bacterial infections. This research evaluated molecular toxicological property of SA exposed to varied concentrations of aqueous HU fruit extract ranging from 500 to 3.90625 µg/µL using broth microdilution method and quantification of AGR I and II genes’ expression employing two-step reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). We first identified quality and quantity of chemical compounds in aqueous fruit of HU using phytochemistry and hybrid gas chromatograph–mass spectrometer (GC–MS) technique. Additionally, preliminary bactericidal potential of HU was assessed before molecular toxicology.ResultsResults revealed six phytochemicals and twenty analytical grade compounds from a standard library were identified from chromatograms of HU fruit extract. Some main compounds detected are n-Hexadecanoic acid (25.24%), 2-Pentadecanone, 6,10,14-trimethyl (16.08%), Cuparene (16.63%), Tetradecanoic acid (6.21%) and 9-Octadecenoic acid, (E)- (5.70%). Bactericidal activity shows significant (p < 0.05) toxicity in the tested (8) concentrations of HU fruits in a dose-response relationship compared to the controls (positive and negative). The quantified expression of AGR I and II genes in SA was most significantly increased (p < 0.05) at both 250 and 500 µg/µL of HU fruit extract while least significant increase (p < 0.05) was recorded at 125 µg/µL compared to control.ConclusionsNotably, the study highlighted a potential risk of augmented bacterial infection especially with higher doses of HU extracts during boils’ treatment and other epidermal infections instigated by Staph. Expression of both AGR genes at higher doses (250 and 500 µg/µL) is indicative of further expression of several other genes responsible for virulence factors in a variety of human bacterial infections. Thus, consumption of HU fruit to treat boils and blisters should be with great caution especially at high doses.

Assessment of energy consumption and environmental safety measures in a plasma pyrolysis plant for eco-friendly waste treatment

A plasma pyrolysis plant with a 50 kg/h installed capacity is investigated for its performance in terms of energy consumption, carbon emission, and environmental safety. Municipal Solid Waste (MSW), precisely the combustible fraction, is processed at approximately 1000 °C. A temperature shoot study is conducted to reduce the energy required for waste processing, revealing a total energy consumption of 0.586 kWh per kg of waste, leading to a reduction of ∼15%. A mass and energy balance has been done to get a clear understanding of different products, by-product generation, and heat losses during waste treatment. The gas analysis identified CO and H2 as dominant components, comprising around 30% of the produced gases, with a lower heating value (LHV) of 4.7 MJ/Nm3. The cold gas efficiency ranges from 44 to 53%. The Energy Dispersive X-ray (EDX) and Inductively Coupled Plasma Mass Spectrometer (ICP-MS) techniques characterize the ash generated during the process and are found carbonless and non-toxic in nature. The wastewater produced during gas cleaning exhibited a neutral acidic nature, with total dissolved solids (TDS) ranging from 1200 to 1500 mg/l. These findings contribute to the plant's promising role in sustainable waste management practices, highlighting its potential as an environmentally sound solution for processing waste.

Joint forces of mass spectrometric techniques (ICP-MS and MALDI-TOF-MS) and fluorescence spectrometry in the study of platinum-based cytostatic drugs interactions with metallothionein MT2 and MT3

Herby, the interaction of metallothioneins with commonly used Pt-based anticancer drugs – cisplatin, carboplatin, and oxaliplatin - was investigated using the combined power of elemental (i.e. LA-ICP-MS, CE-ICP-MS) and molecular (i.e. MALDI-TOF-MS) analytical techniques providing not only required information about the interaction, but also the benefit of low sample consumption. The amount of Cd and Pt incorporated within the protein was determined for protein monomers and dimer/oligomers formed by non-oxidative dimerization. Moreover, fluorescence spectrometry using Zn2+-selective fluorescent indicator – FluoZin3 - was employed to monitor the ability of Pt drugs to release natively occurring Zn from the protein molecule. The investigation was carried out using two protein isoforms (i.e. MT2, MT3), and significant differences in behaviour of these two isoforms were observed.The main attention was paid to elucidating whether the protein dimerization/oligomerization may be the reason for the potential failure of the anticancer therapy based on these drugs. Based on the results, it was demonstrated that the interaction of MT2 (both monomers and dimers) interacted with Pt drugs significantly less compared to MT3 (both monomers and dimers). Also, a significant difference between monomeric and dimeric forms (both MT2 and MT3) was not observed. This may suggest that dimer formation is not the key factor leading to the inactivation of Pt drugs.

High-resolution mass spectrometric elucidation of electron ionization induced fragmentation pathways of methylated warfarin and selected hydroxylated species

The plant secondary metabolite families of coumarin and 4-hydroxy coumarin have a broad pharmacological spectrum ranging from antibacterial to anticancer properties. One prominent member of this substance class is the synthetic but naturally inspired anticoagulant drug and rodenticide warfarin (coumadin). A vast number of publications focus on the identification of warfarin and its major cytochrome P450-mediated phase I metabolites by liquid chromatography (LC) with mass spectrometry (MS) and tandem mass spectrometric (MS/MS) detection techniques. For the first time, electron ionization (EI) induced high-resolution quadrupole time-of-flight mass spectrometric (HR-qToF-MS) data of in-liner derivatized warfarin and selected hydroxylated species is provided in this study as an alternative to LC-MS/MS approaches. Furthermore, the characteristic fragments and fragmentation pathways of the analyzed methyl ethers are concluded. The obtained data of analytical standards, specific deuterated and 13C-labeled compounds prove inductive cleavage of the acyl or acetonyl side chain, methyl migration, and H-migration, along with consequential inductive cleavage as predominant fragmentation routes. Based on the HR-spectral data, commonalities and differences between the analyzed compounds and fragment groups were evaluated with future applicability in structure elucidation and spectra prediction of related compounds.

Pyrroloquinolones B–F: Five unusual alkaloids from Vernonia glabra (Steetz) Vatke (Asteraceae)

Five unusual alkaloids featuring a pyrrolo[1,2-a]quinolone skeleton (pyrroloquinolones B–F, 1–5) were isolated from the ethanol extract of the whole plant of Vernonia glabra (Steetz) Vatke, along with sixteen known compounds. Their structures were established by means of spectroscopic (1D and 2D NMR, UV, IR, and ECD) and high resolution mass spectrometric techniques as well as by comparison of their spectroscopic data with those reported in the literature. The ethanol extract and some isolated compounds were assessed for their antibacterial activity against four bacterial strains. The extract was significantly active against Staphylococcus aureus ATCC1026 and S. epidermidis ATCC35984 (MIC = 64 μg/mL). All the tested compounds showed moderate activity against S. epidermidis (16 ≤ MIC ≤ 64 μg/mL). Furthermore, this is the first report on tricyclic pyrrolo[1,2-a]quinolone alkaloids from a plant source. A biosynthetic pathway for the formation of these compounds is also proposed.

Neutralization of Anthropogenic Acidic Particles by NH3 From Wildfire Over Tropical Peatland

AbstractAcidity is an essential characteristic of aerosol particles that influences chemical and physical properties. Aerosol particles in tropical Asia, such as Singapore, have been reported as highly acidic due to intense anthropogenic sulfur emissions. At the same time, the region has also been experiencing wildfire over tropical peatlands, which is recognized as an intense source of NH3. Here, we investigated the role of NH3 from wildfire on aerosol particles in Singapore by employing the aerosol mass spectrometric technique. The observation was conducted both during wildfire haze (2015 October and 2019 September–October) and non‐haze (2018 October and 2019 April) periods. The observation result demonstrated that inorganic ionic species in Singapore were neutralized by NH4+ during the haze periods. Namely, the degree of neutralization of aerosol particles (i.e., measured NH4+ concentration/predicted NH4+ concentration by assuming that NH4+ fully neutralized SO42−, NO3−, and Cl−) was lower than 0.77during the non‐haze periods. On the other hand, the corresponding values were higher than 0.93 during the haze periods. In addition, NO3− concentration during the daytime of the haze period in 2015 was higher than that in other observation periods. A thermodynamic model calculation suggested that the regime shifts from the “NH3 sensitive region” to the “NH3 and HNO3 sensitive region” or “HNO3 sensitive region” might have occurred during the haze period. In the future, continuous monitoring of both gas‐ and particle‐phase inorganic chemical species will need to be conducted to investigate the impact of wildfire haze on atmospheric chemical processes in more detail.