Identification Of Substances Research Articles

Non-invasive detection of hazardous materials with a thermal-to-epithermal neutron station: a feasibility study towards practical application

The growing scale of the devastation that even a single terrorist attack can cause requires more effective methods for the detection of hazardous materials. In particular, there are no solutions for effectively monitoring threats at sea, both for the off-shore infrastructure and ports. Currently, state-of-the-art detection methods determine the density distribution and the shapes of tested subjects but only allow for a limited degree of substance identification. This work aims to present a feasibility study of the possible usage of several methods available on the thermal-to-epithermal neutron station, VESUVIO, at the ISIS neutron and muon spallation source, UK, for the detection of hazardous materials. To this end, we present the results of a series of experiments performed concurrently employing neutron transmission and Compton scattering using melamine, a commonly used explosive surrogate, in order to determine its signal characteristics and limits of detection and quantitation. The experiments are supported by first-principles modelling, providing detailed scrutiny of the material structure and the nuclear dynamics behind the neutron scattering observables.

Identification of Key Toxic Substances Considering Metabolic Activation: A Combination of Transcriptome and Nontarget Analysis.

There have been numerous studies using effect-directed analysis (EDA) to identify key toxic substances present in source and drinking water, but none of these studies have considered the effects of metabolic activation. This study developed a comprehensive method including a pretreatment process based on an in vitro metabolic activation system, a comprehensive biological effect evaluation based on concentration-dependent transcriptome (CDT), and a chemical feature identification based on nontarget chemical analysis (NTA), to evaluate the changes in the toxic effects and differences in the chemical composition after metabolism. Models for matching metabolites and precursors as well as data-driven identification methods were further constructed to identify toxic metabolites and key toxic precursor substances in drinking water samples from the Yangtze River. After metabolism, the metabolic samples showed a general trend of reduced toxicity in terms of overall biological potency (mean: 3.2-fold). However, metabolic activation led to an increase in some types of toxic effects, including pathways such as excision repair, mismatch repair, protein processing in endoplasmic reticulum, nucleotide excision repair, and DNA replication. Meanwhile, metabolic samples showed a decrease (17.8%) in the number of peaks and average peak area after metabolism, while overall polarity, hydrophilicity, and average molecular weight increased slightly (10.3%). Based on the models for matching of metabolites and precursors and the data-driven identification methods, 32 chemicals were efficiently identified as key toxic substances as main contributors to explain the different transcriptome biological effects such as cellular component, development, and DNA damage related, including 15 industrial compounds, 7 PPCPs, 6 pesticides, and 4 natural products. This study avoids the process of structure elucidation of toxic metabolites and can trace them directly to the precursors based on MS spectra, providing a new idea for the identification of key toxic pollutants of metabolites.

A novel turbidity compensation method for water measurements by UV/Vis and fluorescence spectroscopy

The study presented here addresses the influence of turbidity on UV/Vis spectroscopy measurements of water bodies, a factor that affects the accurate identification and quantification of substances. The novelty of the developed turbidity compensation method is its applicability over the entire UV/Vis spectrum (250 – 900 nm), enabling the accurate detection of substances which appear in the UV/Vis spectrum at higher wavelengths (e.g. chlorophylls), and at high turbidity amounts. Commonly used approaches for turbidity compensation bases on the relationship before and after its correction through mapping functions or subtracting the turbidity-related absorbance from the original spectrum. However, these methods usually consider only certain wavelength ranges, such as 200 – 400 nm, and often reach limitations when applied to real water samples due to increase of turbidity. A significant improvement in our method was achieved by simultaneous determination of turbidity in the sample using scattered light measurement at 850 nm. This information was then applied to generate a turbidity-compensation curve, which was then used to correct the absorption spectrum according to Lambert-Beer’s law. The experimental results show that this novel method reduces the root mean square error (RMSE) from 0.5935 mg L–1 to 0.0218 mg L–1 of the rhodamine B predictions. For better comparability, COD measurements were also carried out and an RMSE of 0.3096 mg L–1 and an R2 of 0.979 were obtained. In summary, it corrects the absorbance deviation caused by turbidity, improves the accuracy of substance prediction and works even at low substance concentrations in turbid solutions or for realistic measurements.

Effect-directed analysis of endocrine and neurotoxic effects in stormwater depending discharges

The investigation of pollutant inputs via stormwater runoff and subsequent effects in receiving waters is becoming increasingly urgent in view of climate change with accompanying extreme weather situations such as heavy rainfall events. In this study, two sampling areas, one urban and one rural but dominated by a highway, were investigated using effect-directed analysis to identify endocrine and neurotoxic effects and potentially responsible substances in stormwater structures and receiving waters. For this purpose, a transgenic yeast cell assay for the simultaneous detection of estrogenic, androgenic, and progestogenic effects (YMEES) was performed directly on high-performance thin-layer chromatography (HPTLC) plates. Concomitantly, estrogens were analyzed by GC–MS/MS and other micropollutants typical for wastewater and stormwater by LC-MS/MS. Discharges from the combined sewer overflow (CSO) contribute a large portion of the endocrine load to the studied water body, even surpassing the load from a nearby wastewater treatment plant (WWTP). An effect pattern similar to the CSO sample was shown in the receiving water after the CSO with lower intensities, consisting of an estrogenic, androgenic, and progestogenic effect. In contrast, after the WWTP, only one estrogenic effect with a lower intensity was detected. Concentrations of E1, 17α-E2, 17β-E2, EE2, and E3 in the CSO sample were 2000, 410, 1100, 560, and 2700 pg/L, respectively. HPTLC-YMEES and GC–MS/MS complement each other very well and help to elucidate endocrine stresses. An Acetylcholinesterase (AChE) inhibitory effect could not be assigned to a causative compound by suspect and non-target analysis using LC-HRMS. However, the workflow showed how information from HPTLC separation, effect-based methods, and other meta-information on the sampling area and substance properties can contribute to an identification of effect-responsible substances. Overall, the study demonstrated that effect-based methods in combination with HPTLC and instrumental analysis can be implemented to investigate pollution by stormwater run-off particularly regarding heavy rain events due to climate change.

Extraction and identification of bioactive compounds from areca nut (Areca catechu L.) and potential for future applications

AbstractAreca (Areca catechu L.) nut is a tropical plantation fruit cultivated mainly in South and Southeast Asia. As a chewing hobby, it has become the most common psychoactive substance in the world, besides tobacco, alcohol, and caffeine. Areca catechu contains abundant nutrients and active components such as alkaloids, polyphenols, polysaccharides, proteins, and vitamins, which have been reported to have anti‐inflammatory, antioxidant, antibacterial, anti‐depressant, anti‐hypertensive, anti‐fatigue, and other biological properties. However, at present, the resource utilization rate of the whole‐plant areca nut is low, which not only causes resource waste but also damages the environment. Establishing effective, safe, and environmentally friendly techniques and methods is necessary for the comprehensive utilization of A. catechu resources. In this review, we summarized the traditional and advanced methods for the extraction and identification of main bioactive substances in A. catechu and compared the advantages and disadvantages of these methods. Furthermore, the possible trends and perspectives for future use of A. catechu are also discussed. Our objective is to extend the application of this bioactive ingredient to improve the added value, provide valuable information for developing new A. catechu products and derivatives, and improve the comprehensive utilization of areca nut resources.

Comprehensive Identification of the Chemical Substances in Effective Component Groups of Polygalae Radix Based on Targeted Tandem Mass Spectrometry Analysis Strategy

ABSTRACTPolygalae Radix is a commonly used traditional Chinese medicine with multiple pharmacological activities. Modern research have revealed that saponins, xanthones, and oligosaccharide esters are its effective component groups. However, up to date the chemical substances in these effective component groups are still unclear, which has become a fundamental scientific issue needing to be addressed. In our study, an analysis strategy based on targeted tandem mass spectrometry (MS/MS) analysis was proposed to comprehensively identify the chemical substances in effective component groups. First, the extract of the Polygalae Radix was detected by ultra‐performance liquid chromatography coupled with electrospray ionization–orbitrap mass spectrometry in a full MS scan mode to minimize the losses of signals; second, the precursor ions of all compounds were extracted from the obtained full MS scan data using Compound Discoverer software; third, the interested precursor ions were locked based on their molecular features and constructed in a precursor ion list; finally, each precursor ion in the list was subjected to targeted MS/MS analysis for structure characterization. Using our analysis strategy, a total of 565 components were successfully identified.

Fourier-transform infrared spectroscopy with undetected photons from high-gain spontaneous parametric down-conversion

Fourier-transform infrared spectroscopy (FTIR) is an indispensable analytical method that allows label-free identification of substances via fundamental molecular vibrations. However, traditional FTIR spectrometers require mid-infrared (MIR) elements, including low-efficiency MIR photodetectors. SU(1,1) interferometry has previously enabled FTIR with undetected MIR photons via spontaneous parametric down-conversion in the low-parametric-gain regime, where the number of photons per mode is much less than one and sensitive photodetectors are needed. In this work, we develop a high-parametric-gain SU(1,1) interferometer for MIR-range FTIR with undetected photons. Using our method, we demonstrate three major advantages: a high photon number at the interferometer output, a considerably lower photon number at the sample, and improved interference contrast. In addition, we broaden the spectral range of the interferometer by aperiodic poling in the gain medium. Exploiting the broadband SU(1,1) interferometer, we measure and evaluate the MIR absorption spectra of polymers in the 3-μm region.

Enhanced terahertz vibrational absorption spectroscopy using an integrated high-Q resonator

The terahertz (THz) absorption spectrum is a powerful method to identify substances. The improvement focuses on sensitivity and recovery ability. Here, we demonstrate enhanced THz vibrational absorption spectroscopy based on an on-chip THz whispering gallery mode resonator (THz-WGMR). A THz-WGMR with high Q can store energy and enhance the interaction between the THz waves and the target substances to capture the unique absorption fingerprint information. Therefore, it possesses significant sensitivity to identify trace amounts of substances. As a proof of concept, lactose powder and glucose powder are applied to demonstrate the effectiveness of our approach in recovering fingerprint absorption spectroscopy. Compared with a straight waveguide, the high sensitivity of the THz-WGMR is illustrated. The change of the transmissivity caused by the lactose reaches 7.8 dB around 532 GHz for the THz-WGMR, while only 1.4 dB for the straight waveguide, demonstrating the state-of-the-art sensing performance in fingerprint absorption recovery. We believe the proposed integrated THz-WGMR will promote the THz identification of tiny fingerprint substances.

An introduction to environmental neurotoxicology: Lessons from a clinical perspective

In 1992, the Committee on Neurotoxicology and Models for Assessing Risk of the National Academy of Sciences in Washington DC focused with a scientific perspective on the identification of substances with neurotoxic potential, studies of exposed populations, risk assessment, and biologic markers of disease. This Committee recommended: “all physicians should be trained to take a thorough occupational-exposure history and to be aware of other possible sources of toxic exposure”. Although convened after several outbreaks of neurotoxic syndromes, clinical neurological considerations were lacking. After defining keys words, namely Environment, Neurotoxicology and Neurotoxicants, we present some demonstrative cases; e.g., the Epidemic Neuropathy in Cuba, Minamata disease, ALS/PDC on Guam, and the ALS hot spot in the French Alps. Always with a clinical and practical approach, we will then review the milieux that contain and convey potential neurotoxicants, the different exposure routes and the clinical presentations. Drawing lessons from clinical cases, we offer some thoughts concerning the future of Environmental Neurotoxicology (ENT). Pointing notably to the diffuse chemical contamination of ecosystems and living beings, including Homo sapiens, we question the real impact of agents with neurotoxic potential on the human brain, considering the effects, for example, of air pollution, endocrine disruptors and nanoparticles. Concern is expressed over the lack of knowledge of the non-monotonic kinetics of many of these chemicals, the major concern being related to mixtures and low-dose exposures, as well as the delayed appearance in clinical expression of prevalent neurodegenerative diseases.

Stevens Johnson Syndrome and Toxic Epidermal Necrolysis Updates on Management

Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are dermatologic emergencies characterized by extensive epidermal necrolysis and sloughing. The incidence rates vary depending on location, with the UK experiencing an annual incidence of 5.76 cases per million individuals from 1995 to 2013. Females are more frequently afflicted than males, with mortality rates ranging from 4.8-9% to 14.8-48%. Nonpharmacologic treatment for SJS/TEN patients includes supportive care, fluid and electrolyte management, infection control, and wound care. The most critical component is the identification and cessation of the causative substance. Management of fluid, electrolytes, and nutrition is crucial for SJS/TEN patients, as they have lower fluid requirements than burn patients. Prophylactic antibiotics do not enhance outcomes, but infection prevention requires appropriate wound care and antiseptic handling. The role of surgical debridement has been a topic of controversy, and the decision to pursue this treatment option depends on the location of care. Anti-shear therapy, which involves aspiration of blister fluid and preservation of denuded epidermis, has been shown to be effective in reducing mortality rates. Pharmacologic treatment for SJS/TEN has been the subject of few prospective studies due to the disease's rarity. Various treatment regimens involving corticosteroids, IVIg, cyclosporine, and TNF-alpha inhibitors have been reported, but it is challenging to determine whether the disease's remission was due to a specific treatment or the natural course of the disease.

Stevens Johnson Syndrome Review

Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are dermatologic emergencies that are distinguished by extensive epidermal necrolysis and sloughing. The incidence rates are location-dependent. Mortality rates vary from 4.8-9% to 14.8-48%, with females being more frequently affected than males. Supportive care, infection control, wound care, and fluid and electrolyte management comprise nonpharmacologic treatment for SJS/TEN patients. The identification and cessation of the causative substance are the most critical components. The management of fluid, electrolytes, and nutrition is essential for SJS/TEN patients, as they have lower fluid requirements than burn patients. Prophylactic antibiotics do not improve outcomes; however, infection prevention necessitates appropriate wound care and antiseptic handling. The decision to pursue surgical debridement is contingent upon the location of care, and the function of this treatment option has been a subject of controversy. Anti-shear therapy, which entails the preservation of denuded epidermis and the aspiration of blister fluid, has been demonstrated to be effective in decreasing mortality rates. The disease's rarity has resulted in a scarcity of prospective studies on pharmacologic treatment for SJS/TEN. There have been reports of a variety of treatment regimens that involve corticosteroids, IVIg, cyclosporine, and TNF-alpha inhibitors. However, it is difficult to ascertain whether the disease's remission was caused by a specific treatment or the natural course of the disease. Studies have demonstrated that supportive care and cyclosporine have the potential to serve as alternative treatments for SJS/TEN. A meta-analysis of 10 studies revealed that patients who received cyclosporine had a survival advantage, while a meta-analysis of 67 studies revealed that the combination of corticosteroids and IVIg resulted in statistically significant improvements in outcomes. The severity of illness scores in patients with SJS/TEN overlap or TEN was reduced by plasmapheresis, which entails plasmapheresis and corticosteroids. In 86.8% of patients, TNF-alpha inhibitors have also demonstrated positive outcomes, despite their immunosuppressive properties. Nevertheless, the most effective pharmacological treatment for SJS/TEN must be determined by taking into account practical factors, such as cost. There is a lack of consensus regarding the most effective treatment, and additional research is required to ascertain the most effective treatment.

Exploring the mechanism of Sendeng-4 against rheumacid arthritis through integrated serum pharmacochemistry, transcriptomics, and network pharmacology.

Mongolian medicine Sendeng-4 (SD-4) has demonstrated satisfactory clinical treatment outcomes for rheumatoid arthritis (RA); nevertheless, its bioactive components and the related mechanisms have not yet been clearly elucidated. To explore the bioactive chemical components of SD-4 in the treatment of RA and its possible mechanisms, an High Performance Liquid Chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established to simultaneously quantify the main components in SD-4, and ultraperformance LC-Q-Exactive-MS/MS (UPLC-Q-Exactive-MS/MS) was used to identify the phytochemicals absorbed in the serum. Then, using network pharmacology methods, these components were constructed into a compound-target network of RA to predict possible biological targets of SD-4 as well as potential signaling pathways. Transcriptomics analysis and molecular docking were used to validate the results of network pharmacology. Subsequently, we established a complete Freund's adjuvant-induced RA rat model and observed the anti-RA effects of SD-4 through assessments of foot swelling, ankle diameter, arthritis score, morphology, serum inflammatory factors, and histopathological analysis of synovial tissue. Specifically, reverse transcription-quantitative polymerase chain reaction, Western blot, and immunohistochemical analysis were used in animal experiments to validate the pathways of serum phytochemistry, network pharmacology, and transcriptomics. Tannic acid, gallic acid, corilagin, crocin I, gardenoside, ferulic acid, quercetin, limonin, rutin, chlorogenic acid, verbascoside, catechin, epicatechin, myricetin, and dihydromyricetin in SD-4 showed good linearity within their respective concentration ranges (r ≥ 0.9991); the average recovery rate was 93.77%-109.17% (relative standard deviation < 2%). A total of 37 compounds were identified in serum samples. Based on this, network pharmacology methods collected 739 genes related to these identified compounds in SD-4 and 3807 genes related to RA. Network pharmacology and transcriptomic analysis demonstrated that the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) signaling pathway is the most relevant pathway affected by SD-4 in RA. In the experiments, SD-4 treatment reduced ankle swelling and arthritis scores in RA rats, improved symptoms, and reduced the production of inflammatory factors. Compared with the RA model group, SD-4 treatment significantly reduced the expression of PI3K-Akt pathway-related messenger RNA and proteins. In addition, immunohistochemical analysis confirmed these results. This study combined serum phytochemistry, network pharmacology, and transcriptomics to demonstrate that SD-4 can alleviate RA by regulating the PI3K-Akt signaling pathway. This research provides a theoretical basis for the clinical application of SD-4 and offers an effective strategy for the identification of bioactive substances in traditional Chinese medicine formulas and the study of their potential mechanisms.

Two-Dimensional Deep Learning Frameworks for Drug-Induced Cardiotoxicity Detection.

The identification of drug-induced cardiotoxicity remains a pressing challenge with far-reaching clinical and economic ramifications, often leading to patient harm and resource-intensive drug recalls. Current methodologies, including in vivo and in vitro models, have severe limitations in accurate identification of cardiotoxic substances. Pioneering a paradigm shift from these conventional techniques, our study presents two deep learning-based frameworks, STFT-CNN and SST-CNN, to assess cardiotoxicity with markedly improved accuracy and reliability. Leveraging the power of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) as a more human-relevant cell model, we record mechanical beating signals through impedance measurements. These temporal signals were converted into enriched two-dimensional representations through advanced transformation techniques, specifically short-time Fourier transform (STFT) and synchro-squeezing transform (SST). These transformed data are fed into the proposed frameworks for comprehensive analysis, including drug type classification, concentration classification, cardiotoxicity classification, and new drug identification. Compared to traditional models like recurrent neural network (RNN) and 1-dimensional convolutional neural network (1D-CNN), SST-CNN delivered an impressive test accuracy of 98.55% in drug type classification and 99% in distinguishing cardiotoxic and noncardiotoxic drugs. Its feasibility is further highlighted with a stellar 98.5% average accuracy for classification of various concentrations, and the superiority of our proposed frameworks underscores their promise in revolutionizing drug safety assessments. With a potential for scalability, they represent a major leap in drug safety assessments, offering a pathway to more robust, efficient, and human-relevant cardiotoxicity evaluations.

Risk Identification of Hazardous Biological and Chemical Substances in Work Safety Efforts

Latar Belakang: Laboratorium pendidikan merupakan salah satu sistem penunjang akademik dan memiliki peran dalam meningkatkan kualitas pendidikan, khususnya di perguruan tinggi. Kegiatan di laboratorium pendidikan yang menggunakan bahan biologi dan kimia berpotensi menimbulkan infeksi dan kontaminasi terhadap pekerja laboratorium dan lingkungan sekitarnya. Oleh karena itu, penelitian ini bertujuan untuk mengidentifikasi dan menganalisis standar operasional penggunaan bahan biologi dan kimia berbahaya serta praktik keselamatan kerja di laboratorium pendidikan di Universitas Jember.Metode: jenis penelitian ini adalah deskriptif observasional. Lokasi penelitian yang diamati adalah sembilan laboratorium pendidikan. Variabel yang diamati dalam penelitian ini adalah SOP penggunaan bahan biologi (7 komponen) dan SOP penggunaan bahan kimia berbahaya (8 komponen).Hasil: Hasil observasi dan analisis menunjukkan bahwa laboratorium mikrobiologi, laboratorium biologi molekuler dan bioteknologi, laboratorium kedokteran molekuler, dan laboratorium biomaterial dan rekayasa bioproses memiliki standar yang baik dalam penggunaan bahan biologi (menerapkan 6 dari 7 komponen). Sementara itu, standar penggunaan bahan kimia berbahaya di laboratorium biologi molekuler dan bioteknologi dan laboratorium molekuler cukup baik (menerapkan 6 dari 8 komponen).Simpulan: berdasarkan komponen standar di laboratorium pendidikan tersebut, setidaknya ada dua standar yang sudah diterapkan, yaitu mencuci tangan menggunakan Alat Pelindung Diri (APD) saat bekerja dengan bahan berbahaya di laboratorium. ABSTRACTBackground: Educational laboratories are an academic supporting system and have a role in improving educational quality, especially in tertiary institutions. Activities in educational laboratories that use biological and chemical materials can potentially cause infection and contamination of laboratory workers and the surrounding environment. Thus, this research aims to identify and analyze operational standards for the use of hazardous biological and chemical substances and work safety practices in educational laboratories at the University of Jember. Methods: This type of research is descriptive observational. The research locations were in nine educational laboratories. The variables observed in this study were SOPs using hazardous biological materials (7 components) and SOPs using chemicals (8 components). Result: The observation and analysis results showed that the Laboratory of Microbiology, Laboratory of Molecular Biology and Biotechnology, Laboratory of Molecular Medicine, and Laboratory of Biomaterials and Bioprocess Engineering had good standards for using hazardous biological materials (applying 6 out of 7 components). Meanwhile, standards for using chemicals in the Laboratory of Molecular Biology and Biotechnology and the Laboratory of Molecular Medicine were also quite good (applying 6 out of 8 components). Conclusions: Based on these standard components in the educational laboratory, at least two standards have been implemented, such as washing hands and using Personal Protective Equipment (PPE) while working on hazardous substances in the laboratory.

Compact three-dimensional fluorescence spectroscopy and its application in food safety

Three-Dimensional fluorescence spectroscopy is an indispensable tool for identification of substances by virtue of its ability to supply abundant characteristic information and high spectral resolution. In this work, we present a compact three-dimensional fluorescence spectrometer utilizing 18 different wavelength LEDs as excitation light source, instead of the conventional bulky multi-wavelength illumination strategy. This spectrometer can in situ obtain the spectral information accurately and fast, while reducing the weight and volume of system. To show its broad biochemical utility, we utilize the compact spectrometer to measure four types of vegetable oil samples from different origins, and analyzed their spectral characteristics. Moreover, we construct a deep learning model based on the 2D-CNN network to detect sesame oil adulteration qualitatively and quantitively. The Compact fluorescence spectrometer proposed has the potential to classify and grade food oils in situ, addressing the problem of sesame oil adulteration on the market.

Isolation, Characterization and Identification of Halophilic bacteria from Solar saltern of Khambhat, Gujarat, India

The solar salterns of Khambhat, Gujarat are distinct biological niches distinguished by high salinity levels and harsh environmental circumstances. Our goal in this work was to isolate and characterise bacteria in order to investigate the diversity of microbes found in these saline soils. Standard microbiological procedures were used to isolate the bacteria from samples taken from various depths of the solar saltern ponds. To clarify their taxonomic identity and physiological characteristics, the isolated bacterial strains underwent morphological, biochemical and molecular characterization. Catalase, oxidase and fermentation assays are examples of biochemical studies that shed light on the isolated strains' metabolic capacities. Moreover, the phylogenetic relationships of the isolated bacteria were ascertained through molecular characterization using 16S rRNA gene sequencing. This work advances our knowledge of the microbial ecology of hypersaline environments and highlights the potential uses of bacteria isolated from these settings in biotechnology such as bioremediation, the synthesis of enzymes and the identification of new bioactive substances. To fully utilize these bacteria's biotechnological potential, more research into their functional properties is necessary.

Non-targeted identification and risk assessment of unknown substances in disposable plastic tableware by GC-Orbitrap HRMS

Disposable plastic tableware was widely used and it was particularly important to identify potential hazardous substances in it and evaluate the risk to humans health. In this study, 85 substances were identified in 60 samples (22 bowls, 20 sporks, and 18 straws) by methanol extraction and non-targeted analysis using GC-Orbitrap HRMS. Subsequently, 14 high-risk substances were further screened and their migration in the samples was measured in three food simulants. Finally, based on the proposed safety limit assessment scheme for EU- authorized and unauthorized substances, the risk assessment of exposure to high-risk substances in disposable plastic tableware was performed for three age groups. The results showed that the dibutyl phthalate and bis(2-ethylhexyl) phthalate in some samples exceeded the safety limit value. Overall, the risk of bowls was lower than spock and straws, and the potential exposure risk for young children was higher than that of adults and older children.

Endophytic Fungal Diversity in Hardwickia binata: Bridging the Gap between Traditional and Modern Techniques

Endophytic fungus is crucial for maintaining plant health and defense mechanisms, acting as protective barriers against pathogens, and producing medicinally beneficial bioactive compounds. Genome sequencing and metagenomics have significantly enhanced the understanding of fungal diversity and metabolic capabilities, enabling the identification of new genes and substances. Traditional culture-dependent methods have been complemented by culture-independent techniques, offering a more comprehensive view of fungal diversity. Using both culture-dependent and culture-independent techniques, the present research investigation explored the diversity of endophytic fungi encountered in the foliage of Hardwickia binata. The study examined the topographical characteristics and nutritional content of soil samples collected from the locality of the selected plant sample, H. binata, to better comprehend the effects on the plant’s growth. The balanced nutrient constituted approximately a pH of 7.2, which suggested an alkaline nature and promoted plant development. The ratio of nitrogen, phosphorous, and potassium remained 3:1:1. A total of 25 fungal isolates, categorized into 17 morphotypes, were obtained using the culture-dependent approach; Curvularia and Nigrospora emerged as the most common genera. Furthermore, the prediction of the ITS2 secondary structure supports the identification of species, highlighting a wide variety of fungal species present in H. binata. The culture-independent approach generated 69,570 high-quality sequences, identifying 269 Operational Taxonomic Units (OTUs). The dominant Ascomycota phylum, along with various genera, indicated a rich fungal community associated with H. binata. This study advances the understanding of the endophytic fungus communities that are associated with H. binata and the nature of soil ecology. The findings emphasize the significance of holistic techniques in the study of microbial dynamics within plant systems as well as their implications for ecosystem management and plant health.

Recognition of multi-component compounds based on occurrence time of secondary crest in the fluorescence lifetime attenuation curve

Fluorescence lifetime is the main characteristic parameter of fluorescence. It is a widely used to draw fluorescence lifetime attenuation curves and to fit fluorescence lifetime parameters by using gated detection methods to identify the species of substances. However, the fluorescence attenuation of each fluorophore in a multi-component compound interferes with one another, affecting the accuracy of identification. In this paper, we propose a method to accurately identify substances by using the occurrence time of the secondary crest of the fluorescence lifetime attenuation curve based on the principle of gated detection to measure the fluorescence lifetime. Furthermore, we design a fluorescence lifetime imaging measurement system and select the same areas of interest in the images for analysis and comparison. The average lifetime of the fluorescence and the occurrence time of the secondary crest are considered as the characteristic parameters. We use five commercially available motor engine oils as the experimental samples and compare the recognition performance of different kernel functions based on a support vector machine (SVM). The radial basis kernel function presents the best performance in terms of recognition accuracy and speed. The recognition rates of the SVM model with the average fluorescence lifetime and the occurrence time of the secondary crest in the attenuation curve of the fluorescence lifetime as a feature vector are 76.24% and 74.65%, respectively. The recognition rate of the SVM model which combines them as feature vectors reaches 91.88%. The experimental results demonstrate that the occurrence time of the secondary crest in the attenuation curve of the fluorescence lifetime can be employed as the basis for substance identification in the analysis of the fluorescence characteristics of multi-component compounds, whose recognition accuracy is similar to the average fluorescence lifetime parameter. Moreover, the occurrence time of the secondary crest of the fluorescence lifetime attenuation curve can be implemented to identify multi-component compounds when it is used as a characteristic parameter.

Enhanced detection of lysergic acid diethylamide using Ehrlich reagent and screen-printed electrodes: A hybrid method for application in forensic analysis

In forensic investigations, the presumptive identification of illicit substances, such as Lysergic Acid Diethylamide (LSD), is crucial. While the Ehrlich's colorimetric reagent (EHR) is commonly employed for LSD detection, producing a characteristic colour change, its lack of selectivity often leads to false-positive or misinterpreted results. Addressing this, we propose a novel method combining electrochemical detection with EHR, enhancing selectivity for LSD’s preliminary identification in forensic samples. This method utilizes a screen-printed carbon electrode (carbon-SPE) in a pH 12 phosphate buffer. We observed two irreversible oxidation processes for LSD at Epa= + 0.35 V (Ox1) and + 0.65 V (Ox2), and for EHR at + 0.62 V and + 0.83 V (vs Ag/AgCl). The LSD + EHR combination displayed three distinct irreversible oxidation processes at + 0.35 V, + 0.66 V, and + 0.86 V. This approach provides three analytical responses for LSD identification: (1) colour change post-EHR test; (2) voltammetric detection of LSD’s two oxidation processes on carbon-SPE; (3) decreased peak current of LSD at Ox1 post-reaction after EHR. Additionally, our method facilitates LSD quantification, exhibiting a low limit of detection (LOD) of 0.69 μmol/L, and consistent electrochemical responses (RSD < 3.0 %) using the same or different carbon-SPEs. Interference studies with other illicit drugs underscored the method’s reliability and selectivity in LSD detection. Moreover, addition-recovery studies on real seized samples approached 100 %, and LSD identification was corroborated by QTOF-LC/MS analyses. Therefore, combining voltammetry with carbon-SPE and EHR offers significant potential for a rapid, simple, and selective LSD screening test in forensic analysis.