Complex Matrices Research Articles

Evaluation of High Vacuum Flavor Extraction Device as a Novel Technique for the Extraction of Volatile Compounds

In this study, a high vacuum flavor extraction (HVE) device was developed to address the limitations of traditional extraction methods, such as extended extraction times and artifact generation during high-temperature processes. Firstly, the repeatability and precision of the HVE method were evaluated through quantitative analysis of twelve volatile odor compounds across seven replicate extractions using gas chromatography–flame ionization detection (GC-FID). The results showed that the HVE system achieved a mean relative standard deviation (RSD) of 11.60 ± 1.79% and a recovery rate of 90.55 ± 4.56%, demonstrating its precision and reproducibility. Secondly, the performance of HVE was compared with solvent-assisted flavor evaporation (SAFE) and simultaneous distillation–extraction (SDE) for extracting flavor compounds from fried tilapia mince. The results indicated that HVE was more effective, particularly in extracting aldehydes and pyrazines, which are key contributors to the flavor profile. Finally, sensory evaluations supported these findings, showing that the odor profiles obtained through HVE were most similar to the original sample, with a similarity score of 72.55%, compared to 69.25% for SAFE and 60.29% for SDE. These findings suggest that HVE is a suitable method for the extraction and analysis of volatile compounds in complex food matrices such as fried tilapia mince.

Evaluating the suitability of niches for additive manufacturing production: proposal for a numeric evaluation tool

Additive manufacturing (AM) is a wide set of technologies that can be used for many different scopes. AM is now a well-integrated prototyping and development tool in most industrial endeavours, while proper end-product manufacturing has only seen very specific niche successes. Given the complexity of AM’s matrix, which is full of discontinuities and non-trivial intercorrelations that play a relevant role in product design and development, it should not come as a surprise that not many end-product applications have succeeded in making use of it. This paper argues that understanding AM’s complex matrix and correctly identifying suitable production niches for it are key elements of this issue, a topic for which existing literature and tools are scarce. The analysis of AM’s status quo for end-product manufacturing and the review of existing approaches to integrate these technologies with product development are the basis used in this paper to propose a suitability assessment tool to fill this knowledge gap.

Quantifying allergenic proteins using antibody-based methods or liquid chromatography-mass spectrometry/mass spectrometry: A review about the influence of food matrix, extraction, and sample preparation.

Accurate quantification of allergens in food is crucial for ensuring consumer safety. Pretreatment steps directly affect accuracy and efficiency of allergen quantification. We systematically reviewed the latest advances in pretreatment steps for antibody-based methods and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) protein quantification methods in food. For antibody-based methods, the effects induced by food matrix like decreased allergen solubility, epitope masking, and nonspecific binding are of the upmost importance. To mitigate interference from the matrix, effective and proper extraction can be used to obtain the target allergens with a high protein concentration and necessary epitope exposure. Removal of interfering substances, extraction systems (buffers and additives), assistive technologies, and commercial kits were discussed. About LC-MS/MS quantification, the preparation of the target peptides is the crucial step that significantly affects the efficiency and results obtained from the MS detector. The advantages and limitations of each method for pre-purification, enzymatic digestion, and peptide desalting were compared. Additionally, the application characteristics of microfluidic-based pretreatment devices were illustrated to improve the convenience and efficiency of quantification. A promising research direction is the targeted development of pretreatment methods for complex food matrices, such as lipid-based and carbohydrate-based matrices.

Chitosan supported hetero-metallic bio-nanocomposites for paracetamol removal from homogeneous solutions and heterogeneous mixtures with focused antibacterial studies

Biopolymers infused with bimetallic nanoparticles exhibit a wide range of functionalities necessary for efficiently eliminating diverse water contaminants. However, the protracted production process requires further exploration. As such, present study seeks to optimize microwave-assisted technique for the facile synthesis of cross-linked chitosan (CTS) supported bimetallic-oxide nanoparticles, specifically zinc oxide (ZnO) and iron-oxide (Fe3O4), denoted as CTS-TTP/Zn-Fe. The primary objective is to investigate the efficacy of these beads in the removal of Paracetamol (PCM) from single and complex water matrices while also assessing their antibacterial properties. Characterization includes chemical composition, surface structures, thermal stability, and magnetic properties. The experimental results demonstrated that CTS-TPP/Zn-Fe beads achieved a remarkable PCM removal efficiency of ~99 % (qm = 4.98 mg g−1), with a Zn:Fe mole ratio of 1:1. The experimental data showed good applicability with Freundlich isotherm and chemisorption-supported rate models (R2 > 0.9). To evaluate the long-term viability and practicality of these beads, three crucial field applicability tests were conducted. These encompassed competition studies with other pharmaceuticals, desorption investigations for repeated use, and efficiency evaluations in an ionic solution. Collectively, this research provides a comprehensive understanding, spanning from material design to practical applications, with potential relevance for large-scale wastewater treatment when coupled with appropriate flux control measures.

Rolling Circle Amplification-Enabled Ultrasensitive Point-of-Care Test Method for Aflatoxin B1 in the Environment and Food

Aflatoxin B1 (AFB1) contamination poses a fatal risk to human beings and urgently needs highly sensitive detection for environmental monitoring and food safety. However, the existing challenges are the unsatisfied sensitivity of the immunoassay methods and the complex matrix effect. Rolling circle amplification (RCA) is a promising method for nucleic acid isothermal amplification due to its high specificity and sensitivity. Herein, we constructed a general RCA-based point-of-care test method (RCA−POCT). With biotinylated antibodies, streptavidin, and biotinylated RCA primers, we realized the signal transduction and preliminary signal amplification. In this way, the fluorescent signal of the immunocomplex on the microwells was greatly enhanced. Under optimal conditions, we recorded sensitive detection limits for aflatoxin B1 (AFB1) of 1.94, 16.3, and 37.7 fg/mL (femtogram per microliter), and wide linear ranges with 5 × 10−6 to 5, 5 × 10−5 to 5, and 5 × 10−5 to 5 ng/mL in the irrigation water, field soil, and peanut samples, respectively. Satisfactory recovery, specificity, repeatability, and reproducibility were observed. The RCA−POCT was validated by comparing it to the HPLC method. This work provides a general RCA-assisted detection method for AFB1 in the environment and food.aflatoxin

The combined effects of polystyrene nanoplastics and dissolved organic matter on the environmental bioavailability of carbamazepine

The bioavailability of active pharmaceutical ingredients (APIs) plays a crucial role in determining the toxicity and risk of contaminants in the environment. However, the bioavailability of APIs in complex environmental matrices is still unclear. In this study, the combined effects of polystyrene nanoplastics (PS NPs) with various particle sizes (50, 100, and 1000 nm) and fulvic acid (FA) on the bioavailability of carbamazepine (CBZ) were investigated via negligible depletion solid-phase microextraction (nd-SPME) and Daphnia magna (D. magna) accumulation. The uptake kinetic study revealed that both PS NPs and FA reduced the elimination rate (k2) in most cases. The availability of CBZ to nd-SPME was determined by the hydrodynamic particle size of PS NPs, whereas the bioavailability to D. magna depended on the intrinsic particle size. The CBZ bioavailability was greater in co-exposed matrices due to the attenuated sorption of PS NPs to CBZ by FA modification. Notably, co-exposure of PS NPs and FA resulted in a higher bioaccumulation factor (BAF) of CBZ, probably due to the desorption and reabsorption of particle-associated CBZ. This study demonstrated that both PS NP particle size and FA binding affect the bioavailability of CBZ, and nd-SPME can mimic only the bioaccumulation of CBZ via diffusion.

A novel Co/Zn-ferrite molecularly imprinted polymer-based electrochemical assay for sensing of gallic acid in plant extracts, wine, and herbal supplement.

In this study, a new molecularly imprinted polymer (MIP)-based sensor platform was developed for the electrochemical determination of gallic acid (GAL) in plant extracts, wine, and herbal supplements. Gallic acid is known for its natural antioxidant properties, which play an important role in preventing cell deterioration that can lead to various diseases. In addition, gallic acid has therapeutic potential due to its anticancer, antiinflammatory, antimicrobial, and neuroprotective properties. Accurate analysis of gallic acid in complex matrices, in mixed samples where different components coexist, is necessary to evaluate the efficacy and safety of this compound. Cobalt ferrite-zinc-dihydro caffeic acid (CFO_Zn_DHCA) nanoparticles, sphere-like in shape and 5 ± 1nm in size, were incorporated into the MIP-based electrochemical sensor design to enhance the active surface area and porosity of the glassy carbon electrode (GCE) surface. The functional monomer chosen for this study was aminophenyl boronic acid (3-APBA). In the GAL/CFO_Zn_DHCA/3-APBA@MIP-GCE sensor, which was developed using photopolymerization (PP), 3-APBA as a functional monomer was designed, and obtained in the presence of basic monomer (HEMA), cross-linker (EGDMA), and initiator (2-hydroxy-2-methyl propiophenone) by keeping it under a UV lamp at 365nm. It aims to detect GAL in real samples such as Punica granatum (pomegranate) peel, Camellia sinensis (green and black tea leaves), wine, and herbal supplements. Morphological and electrochemical characterizations of the designed GAL/CFO_Zn_DHCA/3-APBA@MIP-GCE sensor were carried out using scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The linear range for the determination of GAL using the indirect method (5.0mM [Fe(CN)6]-3/-4) was found to be 1.0 × 10-13M-1.0 × 10-12M, and the limit of detection (LOD) and limit of quantification (LOQ) for standard solutions werecalculated as 1.29 × 10-14 and 4.29 × 10-14M, respectively. As a result of the study, the developed MIP-based electrochemical sensor was suitable for detecting GAL with high specificity, selectivity, and sensitivity. Recovery studies were performed to determine the practical applicability of the sensor, and the results were satisfactory. This innovative sensor platform stands out as a reliable and sensitive analytical tool for determining GAL.

Bioaccumulation of β-methylamino-L-alanine (BMAA) by mussels exposed to the cyanobacteria Microcystis aeruginosa

Cyanobacterial blooms are increasingly common in aquatic environments, raising concerns about the health impacts associated with the toxins they produce. One of these toxins is β-methylamino-L-alanine (BMAA), a neurotoxin linked to neurodegenerative diseases. Monitoring BMAA levels in the environment is challenging due to trace concentrations and complex matrices, and new approaches are needed for assessing exposure risk. In this laboratory study, Australian freshwater mussels, Velesunio ambiguus, were exposed to a BMAA-producing cyanobacterium, Microcystis aeruginosa, to assess its accumulation of the toxin over time. A sample preparation and analysis method was developed to allow accurate quantification of BMAA in the mussels at concentrations as low as 0.4 ng/g. Mussels exposed to M. aeruginosa accumulated BMAA, with concentrations increasing over the exposure period. Rapid depuration occurred after exposure to the cyanobacterium ended, with concentrations of BMAA quickly returning to pre-exposure levels. These results demonstrate the potential for mussels to be used as bioindicators in the field for monitoring BMAA levels over time, where rapid depuration is unlikely.

Quantitative 13C-IS pyrolysis-GC-MS lignin analysis: Overcoming matrix effects in animal feed and faeces

Recently, a pyrolysis-GC-MS methodology for specific lignin quantification and structural characterisation was developed, relying on the use of uniformly 13C-labeled polymeric lignin isolate as internal standard (IS). The 13C-IS py-GC-MS method has been validated for grasses, woods, and applied in various showcases. To study the fate of lignin in animals, this method still requires careful validation in animal feeds and, especially complex faecal samples, hence the aim of this work. Hereto, faecal material was collected from pigs fed with wheat straw as lignin source and subjected to the py-GC-MS analytical platform for thorough examination of IS pyrolysis behaviour in terms of response and structural features. Next, 13C-ISpy-lignin contents and corrected Klason lignin contents were compared. Most importantly, we revealed that pyrolysis behaviour of 13C-IS lignin and 12C-sample lignin was differently affected in the faecal matrix, resulting in the ultimate underestimation of 13C-ISpy-lignin contents. In-depth examination and evaluation of matrix constituents showed that predominantly matrix ash was responsible for the effects observed. We further demonstrated that said matrix effects can be overcome by water extraction of the samples prior to analysis. Our validation and approach extend the use of the specific 13C-IS py-GC-MS methodology for accurate quantitative lignin analysis to biomass samples with complex matrices like pig faeces, and now call for application in future digestibility studies.

Performance comparison of modified polyethersulfone membrane with graphene oxide and molybdenum disulfide for effective filtration of urban surface water

In the current water treatment scenario, membrane filtration is a crucial technology due to its ability to effectively remove pollutants, ensuring clean and safe water. However, a significant challenge to its widespread application is membrane fouling, which reduces membrane efficiency and service life. Various membrane modifications have been studied to enhance fouling resistance. In this work, the effect of adding graphene oxide (GO) and molybdenum disulfide (MoS2) nanoparticles for the fabrication of mixed polyethersulfone (PES) membranes was evaluated. The modified membranes were evaluated for pollutant removal efficiency and fouling resistance using model humic acid solutions and surface water samples. The PES-GO membranes demonstrated significantly improved hydrophilicity, up to 43% reduction in protein deposition, and an average flux recovery ratio (FRR) of 63%, superior to the control PES membrane, resulting in reduced fouling and sustained high permeability. Nevertheless, although PES-MoS2 exhibited high rejection rates of dissolved organic matter and UV254, they also showed higher foulant adsorption and lower FRR, likely due to the development of a colloidal fouling when treating more complex water matrices. Attenuated Total Reflectance Fourier-Transform Infrared (ATR-FTIR) analysis confirmed the deposition of organic foulants, with polysaccharides and proteins identified as major contributors to fouling. These findings suggest that while GO-enhanced PES membranes offer improved water treatment performance, modifications with MoS2 require careful consideration of feedwater composition. Future work should focus on optimizing nanoparticle integration and evaluating membrane effectiveness for diverse water sources.

AFB1-responsive mesoporous silica nanoparticles for AFB1 quantification based on aptamer-regulated release of SERS reporter

In this study, we propose a novel surface-enhanced Raman scattering (SERS) method for quantifying aflatoxin B1 (AFB1). This method relies on the target-triggered release of a SERS reporter from aptamer-sealed aminated mesoporous silica nanoparticles (MSNs). These MSNs were synthesized to accommodate 4-mercaptophenylboronic acid (4-MPBA) within their well-defined micropores, which were subsequently sealed with AFB1 aptamers. Upon specific binding of AFB1 to its aptamer, the conformational change in the aptamer is regulated by the presence of the target. Consequently, a positive linear relationship between the AFB1 concentration and the 4-MPBA SERS signal was observed. Under optimal conditions, the method exhibited a good linear relationship over the range of 0.1 to 5 ng/mL AFB1, with a limit of detection (LOD) of 0.03 ng/mL. This strategy was validated using wheat samples, yielding results comparable to high performance liquid chromatography-fluorescence detector (P > 0.05), confirming its reliability for detecting AFB1 in complex food matrices.

Rapid detection of microfibres in environmental samples using open-source visual recognition models

Microplastics, particularly microfibres (< 5 mm), are a significant environmental pollutant. Detecting and quantifying them in complex matrices is challenging and time-consuming. This study presents two open-source visual recognition models, YOLOv7 and Mask R-CNN, trained on extensive datasets for efficient microfibre identification in environmental samples. The YOLOv7 model is a new introduction to the microplastic quantification research, while Mask R-CNN has been previously used in similar studies. YOLOv7, with 71.4 % accuracy, and Mask R-CNN, with 49.9 % accuracy, demonstrate effective detection capabilities. Tested on aquatic samples from Seyðisfjörður, Iceland, YOLOv7 rapidly identifies microfibres, outperforming manual methods in speed. These models are user-friendly and widely accessible, making them valuable tools for microplastic contamination assessment. Their rapid processing offers results in seconds, enhancing research efficiency in microplastic pollution studies. By providing these models openly, we aim to support and advance microplastic quantification research. The integration of these advanced technologies with environmental science represents a significant step forward in addressing the global issue of microplastic pollution and its ecological and health impacts.

Assessment of the Possibility of Using the Trace Element Status of a Herbal Drug as an Additional Quality Criterion: Chamomile Flowers as a Case Study

INTRODUCTION. Herbal drugs can often be difficult to identify and distinguish from morphologically similar species, especially when fractionated. For the analysis of complex mixtures of herbal origin, it is reasonable to use additional identification methods, including hierarchical clustering of herbal drugs by their trace element content.AIM. This study aimed to assess the possibility of using hierarchical clustering by trace element content for complex biological matrices (plant mixtures), with officinal chamomile species as a case study.MATERIALS AND METHODS. Multiple morphologically similar species grow together with officinal chamomile species that are widely used in medical practice. The study examined the flowers and peduncles of Matricaria recutita L., Tanacetum parthenium (L.) Sch.Bip., Leucanthemum vulgare Lam., Tripleurospermum inodorum (L.) Sch.Bip., and Matricaria suaveolens Buchenau, as well as artificial mixtures of chamomile with adulterant species (as samples non-compliant with pharmacopoeial specifi ca tions). The content of trace elements was determined by inductively coupled plasma mass spectrometry (ICP-MS). The statistical treatment of the results used Statistica 10 software with a built-in data analysis algorithm for multivariate experiments.RESULTS. Having determined the content of 56 trace elements, the authors plotted a hierarchical cluster tree using cluster analysis methods. M. recutita and M. suaveolens were shown to be the closest to each other in terms of their trace element status, which correlated with their taxonomy. Artificial plant mixtures formed intermediate clusters that were observed between different chamomile species. Moreover, according to the criterion of dissimilarity, the trace element cluster of M. recutita significantly differed from the trace element clusters of all the adulterant species and mixtures containing more than 10% of the adulterant species.CONCLUSIONS. This study demonstrated the possibility of using hierarchical clustering based on the content of trace elements in a biological object to analyse complex systems, including plant mixtures, and identify differences that may have discriminative value for the quality control of herbal drugs.

Tailoring carbon intercalated α,β-FePc heterophase junction to boost electron transfer for 1O2-dominated photo-Fenton reaction

Construction of 1O2-dominated photo-Fenton reaction (PFR) is of great significance to enhance the compatibility to complicated water matrices, due to the selectivity of 1O2. Herein, a carbon intercalated heterophase junction (α,β-FePc@C) is constructed through a calcination-regulated strategy. The as-synthesized α,β-FePc@C exhibited high efficiency in tetracycline degradation with catalyst-dosage-normalized kinetic rate constant of 1.39 L min-1 g-1, outperforming most previously reported works. Importantly, H2O2 activation follows h+-meditated two-step oxidation, resulting in 1O2-dominated reaction with strong anti-interference performance. Experimental and theoretical evidences reveal that dual phases of α-FePc and β-FePc are strategically retained to form heterophase junction, creating internal electric field to propel the photogenerated carrier separation. Carbon intercalation not only optimizes band structure to promote electron transition but also boosts the electron transfer for H2O2 activation. In general, this work presents a facile strategy of constructing photocatalyst for 1O2-dominated PFR and sheds light on upgrading the adaptability of PFR to complex water matrices.

CE-MS-Based Clinical Metabolomics of Human Plasma.

Capillary electrophoresis coupled to mass spectrometry (CE-MS) has emerged as a powerful analytical technique with significant implications for clinical research and diagnostics. The integration of information from CE and MS strengthens confidence in the identification of compounds present in clinical samples. The ability of CE to separate molecules based on their electrophoretic mobility coupled to MS enables the accurate identification and quantification of analytes, even in complex biological matrices such as human plasma.Here, we present a detailed protocol for an untargeted metabolomics study using CE-MS and its application in a study on human plasma from patients suffering Long COVID syndrome. The protocol ranges from sample preparation to biological interpretation, detailing a workflow enabling the analysis of cationic and anionic compounds, metabolite identification, and data processing.

An autocatalytic hybridization circuit-based FRET aptasensor for detection of low-abundant sulfameter in human serum

Exposure to antibiotics is considered a potential risk factor for human health. Yet, the extensive and cost-effective detection of low-abundant antibiotics in complex matrices remains a significant challenge. Herein, an aptamer and an autocatalytic hybridization circuit (AHC) were used to fabricate a fluorescence resonance energy transfer (FRET) platform to detect sulfameter (SME) in human serum. The AHC system comprised two mutually motivated hybridization chain reactions (HCR) modules, ultimately producing long-branched DNA copolymeric nanowires. This mutually reciprocal activation of two HCR modules enables continuous signal amplification, providing the AHC system with wide linear range and high sensitivity for the SME detection. Compared to the HCR-based aptasensor, the AHC-based aptasensor exhibited a wider linear range and improved sensitivity (3.3 times greater). Under optimal conditions, the fluorescent AHC-based aptasensor demonstrated a linear range (R2 was 0.996) from 0.5 to 2000 nM, with a low detection limit of 0.301 nM (S/N = 3). The fluorescent aptasensor was also validated by SME-spiked human serum samples, showing average recoveries ranging from 96.40 % to 109.30 %, with a relative standard deviation below 10.45 %. Furthermore, when tested on six human serum samples, the aptasensor results were consistent with those obtained from the commercial ELISA method. These findings demonstrate that the proposed aptasensor provides a promising approach for the practical monitoring of low-abundant SME in human serum.

Enzyme-accelerated catalytic DNA circuits enable rapid and one-pot detection of bacterial pathogens

Catalytic DNA circuits, serving as signal amplification strategies, can enable simple and accurate detection of pathogenic bacteria in complex matrices but suffer from low reaction rates and depths. Herein, we design an enzyme-accelerated catalytic hairpin assembly (EACHA) in which duplex DNA products are converted into hairpin reactants to continue participating in the next circuit reaction with the assistance of RNase H. Profiting from the high recyclability of the reactants, EACHA exhibits an approximately 37.6-fold enhancement in the rate constant and a two-order-of-magnitude improvement in sensitivity compared to conventional catalytic hairpin assembly (CHA). By integrating an allosteric probe with EACHA, a one-pot method is developed for rapid and direct detection of S. enterica Enteritidis (S. Enteritidis). This method is capable of detecting 15 CFU mL−1 of S. Enteritidis within 20 min, which is superior to that of real-time PCR. By testing 60 milk samples, we demonstrate this method's high accuracy in discriminating contaminated samples, with an area under the curve (AUC) of 0.997. Moreover, this method can be employed to accurately diagnose early-stage infected mice, with an AUC of 1.00 for feces samples and 0.986 for serum samples. Therefore, this study offers a simple and feasible method for identifying pathogens in complex matrices.

Evaluation of extraction and storage conditions for quantification and characterization of silver nanoparticles in complex samples by single particle-ICP-MS

The extraction of nanoparticles (NPs) from complex matrices and subsequent storage can potentially alter the NPs physicochemical properties and hinder cross-study comparisons. Most NP extraction methods are designed and tested at high nanoparticle concentrations, although (eco)toxicological and regulatory monitoring programs require methods capable of analyzing NPs at environmentally relevant concentrations (lower ppb range). In this study, we investigated how extraction methods affect the characteristics of PVP coated and citrate-stabilized silver NPs (AgNPs) spiked into soil, sewage sludge, and biological samples at environmentally relevant concentrations using Single Particle Inductively Coupled Plasma Mass Spectrometry spICP-MS). Further we investigated the impact of storage temperature (-80°C to 21°C) and storage duration (1-28 days) on the particle characteristics such as particle size.We found that aqueous AgNPs samples with low ionic strength media retained their original characteristics (like particle size, particle concentration and particle-based Ag mass) when preserved at 4°C for up to 28 days. AgNPs dispersed in high ionic strength media were however better preserved at -80°C. Among the extraction agents, tetrasodium pyrophosphate was more efficient in extracting AgNPs from soil and sewage sludge matrices, while Proteinase K was more suitable for biological samples from organisms (earthworms or fish).Although our study focused only on AgNPs, it provides crucial information to aid interlaboratory comparisons and data interpretation for (eco)toxicological studies.

Sequential DBD plasma-assisted tandem tri-electrodes Fenton process for enhanced antibiotics treatment and denitrification

Ozone generated by dielectric barrier discharge (DBD) plasma has the potential for water treatment; however, its limitations, including water solubility, performance in complex matrices, and resistance to some pollutants. This study explored a sequential DBD plasma assisted by a tandem tri-electrode Fenton (S-PEF) process, using a three-stage treatment approach for degrading antibiotics (sulfamethoxazole, SMX; amoxicillin, AMX; and norfloxacin, NOF) in continuous flow mode for 220-bed volumes. Initially, antibiotics such as SMX and AMX underwent degradation in DBD plasma gas, which housed the mixing chamber. The more resilient NOF was removed by hydroxyl radicals (OH) in the following anodic chamber of the tandem trielectrodes by Fenton assisted oxidation. The continuous cyclic redox regeneration of Fe in tandem trielectrodes prevents secondary Fe sludge pollution. Finally, NO3-N and NO2-N were denitrified into N2 with 95 % selectivity in a cathodic chamber using copper oxide nanowires. This sequential treatment is crucial to mitigating the competitive effects of CO32− and humic acid in wastewater since O3 is less susceptible to them compared to OH. The S-PEF completely degraded all antibiotics regardless of water temperature (10 and 25 °C) compared to sole plasma treatment. Finally, toxicity assessments using an ecological structure–activity relationship (ECOSAR) and E. coli disinfection assays showed a significant reduction in toxicity. This study highlights the promising potential of the S-PEF as an advanced technology for wastewater treatment.

Characterizing Jordan embeddings between block upper-triangular subalgebras via preserving properties

Let Mn be the algebra of n×n complex matrices. We consider arbitrary subalgebras A of Mn which contain the algebra of all upper-triangular matrices, and their Jordan embeddings. We first describe Jordan embeddings ϕ:A→Mn as maps of the formϕ(X)=TXT−1orϕ(X)=TXtT−1, where T∈Mn is an invertible matrix, and then we obtain a simple criterion of when one block upper-triangular subalgebra Jordan-embeds into another (and in that case we describe the form of such embeddings). As a main result, we characterize Jordan embeddings ϕ:A→Mn (when n≥3) as continuous injective maps which preserve commutativity and spectrum. We show by counterexamples that all these assumptions are indispensable (unless A=Mn when injectivity is superfluous).