An Innovative EEG-Based Pain Identification and Quantification: A Pilot Study.

OBJECTIVE: The present pilot study aimed to propose an innovative scale-independent measure based on electroencephalographic (EEG) signals for the identification and quantification of the magnitude of chronic pain. METHODS: EEG data were collected from three groups of participants at rest: seven healthy participants with pain, 15 healthy participants submitted to thermal pain, and 66 participants living with chronic pain. Every 30 s, the pain intensity score felt by the participant was also recorded. Electrodes positioned in the contralateral motor region were of interest. After EEG preprocessing, a complex analytical signal was obtained using Hilbert transform, and the upper envelope of the EEG signal was extracted. The average coefficient of variation of the upper envelope of the signal was then calculated for the beta (13-30 Hz) band and proposed as a new EEG-based indicator, namely Piqß, to identify and quantify pain. MAIN RESULTS: The main results are as follows: (1) A Piqß threshold at 10%, that is, Piqß ≥ 10%, indicates the presence of pain, and (2) the higher the Piqß (%), the higher the extent of pain. CONCLUSIONS: This finding indicates that Piqß can objectively identify and quantify pain in a population living with chronic pain. This new EEG-based indicator can be used for objective pain assessment based on the neurophysiological body response to pain. SIGNIFICANCE: Objective pain assessment is a valuable decision-making aid and an important contribution to pain management and monitoring.

Deciphering the Properties and Functions of Glycoproteins Using Quantitative Proteomics.

Glycosylation is one of the most common and important protein modifications, and it regulates the properties and functions of a wide range of proteins. Aberrant glycosylation is directly related to human diseases. Recently, with the advancement of mass spectrometry (MS) instrumentation and MS-based glycoproteomic methods, global characterization of glycoproteins in complex biological samples has become possible. Using quantitative proteomics, the abundance of glycoproteins in different samples can be quantified, which provides a wealth of information to further our understanding of protein functions, cellular activities, and the molecular mechanisms of diseases. In this review, we discuss quantitative proteomic methods used for comprehensive analysis of protein glycosylation, and cover the applications of quantitative glycoproteomics to unveil the properties and functions of glycoproteins and their association with various diseases. It is expected that quantitative proteomic methods will be extensively applied to explore the role of protein glycosylation in complex biological systems, and to identify glycoproteins as biomarkers for disease detection and as therapeutic targets for disease treatment.

Essential Components from Plant Source Oils: A Review on Extraction, Detection, Identification, and Quantification.

Oils derived from plant sources, mainly fixed oils from seeds and essential oil from other parts of the plant, are gaining interest as they are the rich source of beneficial compounds that possess potential applications in different industries due to their preventive and therapeutic actions. The essential oils are used in food, medicine, cosmetics, and agriculture industries as they possess antimicrobial, anticarcinogenic, anti-inflammatory and immunomodulatory properties. Plant based oils contain polyphenols, phytochemicals, and bioactive compounds which show high antioxidant activity. The extractions of these oils are a crucial step in terms of the yield and quality attributes of plant oils. This review paper outlines the different modern extraction techniques used for the extraction of different seed oils, including microwave-assisted extraction (MAE), pressurized liquid extraction (PLE), cold-pressed extraction (CPE), ultrasound-assisted extraction (UAE), supercritical-fluid extraction (SFE), enzyme-assisted extraction (EAE), and pulsed electric field-assisted extraction (PEF). For the identification and quantification of essential and bioactive compounds present in seed oils, different modern techniques-such as high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FTIR), gas chromatography-infrared spectroscopy (GC-IR), atomic fluorescence spectroscopy (AFS), and electron microscopy (EM)-are highlighted in this review along with the beneficial effects of these essential components in different in vivo and in vitro studies and in different applications. The primary goal of this research article is to pique the attention of researchers towards the different sources, potential uses and applications of oils in different industries.

Identification and quantification of common microplastics in table salts by a multi-technique-based analytical method.

Microplastics (MPs) are considered as contaminants of emerging concern to the environment and our food chains in recent years. In this study, we presented a multi-technique-based analytical method for detection of MPs through a combination of microscope-FTIR (µ-FTIR) with pyrolysis-GC/MS (Py-GC/MS) to achieve 3-dimensional (3D) information for the identification of polymer type, characterization of particle size and morphology, and quantification of MPs based on both particle number and mass of plastics. Plastics that are commonly used and disposed of, including polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), poly vinyl chloride (PVC), polyamide (PA), and poly(methyl methacrylate) (PMMA), were covered in this study. Sample extraction and separation procedures were optimized for these microplastics in table salts where good recoveries (> 75%) were achieved. To further enhance the detection sensitivity in simultaneous quantification of multiple polymers in a sample, a serial dissolution approach with different solvents was developed for the detection of all 7 types of plastics. The established sample preparation process and multi-technique-based analytical method were validated with polymer standards in table salts, resulting in satisfactory qualification and quantification for all samples tested. A retail survey of MPs in table salts was conducted with the developed analytical method, revealing that MPs were present in all commercially available table salts. The total number of MP particles varied from 20 to 125 particles/kg and the total mass contents of seven types of plastics ranged from 30 to 530 µg/kg in table salts.

Occurrence of Mycosporine-like Amino Acids (MAAs) from the Bloom-Forming Cyanobacteria Aphanizomenon Strains.

Mycosporine-like amino acids (MAAs) are widespread in various microbes and protect them against harsh environments. Here, four different Aphanizomenon species were isolated from severely eutrophic waterbodies, Lake Dianchi and the Guanqiao fishpond. Morphological characters and molecular phylogenetic analysis verified that the CHAB5919, 5921, and 5926 strains belonged to the Aphanizomenon flos-aquae clade while Guanqiao01 belonged to the Aphanizomenon gracile clade. Full wavelength scanning proved that there was obvious maximal absorption at 334 nm through purified methanol extraction, and these substances were further analyzed by HPLC and UPLC-MS-MS. The results showed that two kinds of MAAs were discovered in the cultured Aphanizomenon strains. One molecular weight was 333.28 and the other was 347.25, and the daughter fragment patterns were in accordance with the previously articles reported shinorine and porphyra-334 ion characters. The concentration of the MAAs was calibrated from semi-prepared MAAs standards from dry cells of Microcystis aeruginosa PCC7806 algal powder, and the purity of shinorine and porphyra-334 were 90.2% and 85.4%, respectively. The average concentrations of shinorine and porphyra-334 were 0.307−0.385 µg/mg and 0.111−0.136 µg/mg in Aphanizomenon flos-aquae species, respectively. And there was only one kind of MAAs (shinorine) in Aphanizomenon gracile species.,with a content of 0.003−0.049 µg/mg dry weight among all Aphanizomenon gracile strains. The shinorine concentration in Aphanizomenon flos-aquae was higher than that in Aphanizomenon gracile strains. The total MAAs production can be ranked as Aphanizomenon flos-aquae > Aphanizomenon gracile.

Peak Identification and Quantification by Proteomic Mass Spectrogram Decomposition.

Recent advances in the liquid chromatography/mass spectrometry (LC/MS) technology have improved the sensitivity, resolution, and speed of proteome analysis, resulting in increasing demand for more sophisticated algorithms to interpret complex mass spectrograms. Here, we propose a novel statistical method, proteomic mass spectrogram decomposition (ProtMSD), for joint identification and quantification of peptides and proteins. Given the proteomic mass spectrogram and the reference mass spectra of all possible peptide ions associated with proteins as a dictionary, ProtMSD estimates the chromatograms of those peptide ions under a group sparsity constraint without using the conventional careful preprocessing (e.g., thresholding and peak picking). We show that the method was significantly improved using protein-peptide hierarchical relationships, isotopic distribution profiles, reference retention times of peptide ions, and prelearned mass spectra of noise. We examined the concept of database search, library search, and match-between-runs. Our ProtMSD showed excellent agreements of 3277 peptide ions (94.79%) and 493 proteins (98.21%) with Mascot/Skyline for an Escherichia coli proteome sample and of 4460 peptide ions (103%) and 588 proteins (101%) with match-between-runs by MaxQuant for a yeast proteome sample. This is the first attempt to use a matrix decomposition technique as a tool for LC/MS-based proteome identification and quantification.

Evaluation of a novel real-time PCR assay for the detection, identification and quantification of Plasmodium species causing malaria in humans.

BACKGROUND: The entry of PCR-based techniques into malaria diagnostics has improved the sensitivity and specificity of the detection of Plasmodium infections. It has been shown that humans are regularly infected by at least six different Plasmodium species. The MC004 real-time PCR assay for malaria diagnosis is a novel single-tube assay that has been developed for the purpose of simultaneously detecting all Plasmodium species known to infect humans, and discrimination between Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale wallikeri, Plasmodium ovale curtisi, Plasmodium knowlesi (including differentiation of three strains) and Plasmodium cynomolgi (including differentiation of three strains). Detection and identification of Plasmodium species relies on molecular beacon probe-based melting curve analysis. In addition, this assay might be used to quantify the parasitaemia of at least P. falciparum by calculating the level of parasitaemia directly from the Cq-value. METHODS: The samples used in this study comprised reference samples, patient samples, and synthetic controls. The following analytical performance characteristics of the MC004 assay were determined: analytical specificity, limit of detection, the ability to detect mixed infections, and the potential to determine the level of parasitaemia of P. falciparum, including assessment of within-run and between-run precisions. RESULTS: No false positive or false negative results were observed. The limit of detection of P. falciparum was 1 × 10-3 IU/mL (WHO standard). Mixed infections with P. falciparum and non-falciparum species were correctly identified. A calibration curve could be established to quantify the parasitaemia of at least P. falciparum. The within-run and between-run precisions were less than 20% CV at the tested parasitaemia levels of 0.09%, 0.16%, 2.15% and 27.27%. CONCLUSION: Based upon the analytical performance characteristics that were determined, the MC004 assay showed performance suitable for use in clinical settings, as well as epidemiological studies.

The Donor-Dependent and Colon-Region-Dependent Metabolism of (+)-Catechin by Colonic Microbiota in the Simulator of the Human Intestinal Microbial Ecosystem.

The intestinal absorption of dietary catechins is quite low, resulting in most of them being metabolized by gut microbiota in the colon. It has been hypothesized that microbiota-derived metabolites may be partly responsible for the association between catechin consumption and beneficial cardiometabolic effects. Given the profound differences in gut microbiota composition and microbial load between individuals and across different colon regions, this study examined how microbial (+)-catechin metabolite profiles differ between colon regions and individuals. Batch exploration of the interindividual variability in (+)-catechin microbial metabolism resulted in a stratification based on metabolic efficiency: from the 12 tested donor microbiota, we identified a fast- and a slow-converting microbiota that was subsequently inoculated to SHIME, a dynamic model of the human gut. Monitoring of microbial (+)-catechin metabolites from proximal and distal colon compartments with UHPLC-MS and UPLC-IMS-Q-TOF-MS revealed profound donor-dependent and colon-region-dependent metabolite profiles with 5-(3',4'-dihydroxyphenyl)-γ-valerolactone being the largest contributor to differences between the fast- and slow-converting microbiota and the distal colon being a more important region for (+)-catechin metabolism than the proximal colon. Our findings may contribute to further understanding the role of the gut microbiota as a determinant of interindividual variation in pharmacokinetics upon (+)-catechin ingestion.

Detecting Air Pollutant Molecules Using Tube-Shaped Single Electron Transistor.

An air pollution detector is proposed based on a tube-shaped single-electron transistor (SET) sensor. By monitoring the flow control component of the detector, each air pollutant molecule can be placed at the center of a SET nanopore and is treated as an island of the SET device in the same framework. Electron transport in the SET was incoherent, and the performances of the SET were sensitive at the single molecule level. Employing first-principles calculations, electronic features of an air pollutant molecule within a tube-shaped SET environment were found to be independent of the molecule rotational orientations with respect to axis of symmetry, unlike the electronic features in a conventional SET environment. Charge stability diagrams of the island molecules were demonstrated to be distinct for each molecule, and thus they can serve as electronic fingerprints for detection. Using the same setup, quantification of the air pollutant can be realized at room temperature as well. The results presented herein may help provide guidance for the identification and quantification of various types of air pollutants at the molecular level by treating the molecule as the island of the SET component in the proposed detector.

[Features of determination of 2-methoxyhydroxybenzene in the study of biological material]. / Osobennosti opredeleniya 2-metoksigidroksibenzola pri issledovanii biologicheskogo materiala.

The aim of the study was to develop a method for the determination of 2-methoxyhydroxybenzene in biological material. TLC, UV spectrophotometry, HPLC and GC-MS were used in the experiments. The use of a mixture of ethyl acetate-acetone (7:3 by volume) for the isolation of 2-methoxyhydroxybenzene from biological material is justified. Optimal isolation conditions are established. Purification of the substance was carried out by extraction and chromatography in sorbent column (KCC-3) 80/120 µm. For preliminary identification, TLC was used on Sorbfil PTSX-AF-A-UV plates. Confirmation of identification was carried out by the UV spectrum in ethanol by HPLC with the retention time in a 250×4.6 mm column «SunFire C18¼ (mobile phase acetonitrile-0.025 M potassium dihydrogen phosphate solution 6: 4). Confirmation identification and quantification was performed by GC-MS using a fixed phase capillary column of 5% phenyl-95% methyl polysiloxane after derivatization of the analyte with N-trimethylsilyl-N-methyl trifluoroacetamide (heating for 30 min at a temperature of 60 °C). Ions 45, 58, 73, 91, 107, 136, 151, 166, 181, 196 m/z are present in the mass spectrum of the derivative. The validation of the methodology for the determination of 2-methoxyhydroxybenzene in biomaterial based on the application of the GC-MS method was carried out. The compliance of the methodology with the criteria of linearity, selectivity, correctness, precision and stability is established. The detection limit and the limit of quantification are 8 and 15 µg per 100 g of biomaterial, respectively.

Systematic Analysis of Fatty Acids in Human Cells with a Multiplexed Isobaric Tag (TMT)-Based Method.

Fatty acids (FAs) are essential components in cells and are involved in many cellular activities. Abnormal FA metabolism has been reported to be related to human diseases such as cancer and cardiovascular diseases. Identification and quantification of FAs provide insights into their functions in biological systems, but it is very challenging to analyze them due to their structures and properties. In this work, we developed a novel method by integrating FAs tagged with stable isotope labeled aminoxy tandem mass tags (aminoxyTMTs) and mass spectrometric analysis in the positive mode. On the basis of their structures, the aminoxyTMT reagents reacted with the carboxylic acid group of the FAs, resulting in an amine group with high proton affinity covalently attached to the analytes. This enabled the analysis of FAs under the positive electrospray ionization-mass spectrometry (ESI-MS) mode, which is normally more popular and sensitive compared to the negative mode. More importantly, the multiplexed TMT tags allowed us to quantify FAs from several samples simultaneously, which increased the experimental throughput and quantification accuracy. FAs extracted from three types of breast cells, i.e., MCF 10A (normal), MCF7 (minimally invasive) and MDA-MB-231 (highly invasive) cells, were labeled with the six-plexed aminoxyTMTs and quantified by LC-MS/MS. The results demonstrated that the abundances of some FAs, such as C22:5 and C20:3, were markedly increased in MCF7 and MDA-MB-231 cancer cells compared to normal MCF 10A cells. For the first time, aminoxyTMT reagents were exploited to label FAs for their identification and quantification in complex biological samples in the positive MS mode. The current method enabled us to confidently identify FAs and to accurately quantify them from several samples simultaneously. Because this method does not have sample restrictions, it can be extensively applied for biological and biomedical research.

Monitoring of 943 organic micropollutants in wastewater from municipal wastewater treatment plants with secondary and advanced treatment processes.

To perform a systematic survey on the occurrence and removal of micropollutants during municipal wastewater treatment, 943 semi-volatile organic chemicals in 32 wastewater samples including influents of secondary treatments, secondary effluents and final effluents (effluents of advanced treatments), which were collected from seven full-scale municipal wastewater treatment plants (MWTPs) in China, were examined by gas chromatography-mass spectrometry (GC-MS) coupled with an automated identification and quantification system with a database (AIQS-DB). In total, 196 and 145 chemicals were detected in secondary and final effluents, respectively. The majority of the total concentrations (average removal efficiency, 87.0%±5.9%) of the micropollutants were removed during secondary treatments. However, advanced treatments achieved different micropollutant removal extents from secondary effluents depending on the different treatment processes employed. Highly variable removal efficiencies of total concentrations (32.7%-99.3%) were observed among the different advanced processes. Among them, ozonation-based processes could remove 70.0%-80.9% of the total concentrations of studied micropollutants. The potentially harmful micropollutants, based on their detection frequency and concentration in secondary and final effluents, were polycyclic aromatic hydrocarbons (PAHs) (2-methylnaphthalene, fluoranthene, pyrene, naphthalene and phenanthrene), phosphorus flame retardants (tributyl phosphate (TBP), tris(2-chloroethyl) phosphate (TCEP) and tris(1,3-dichloro-2-propyl) phosphate (TDCP)), phthalates (bis(2-ethylhexyl)phthalate (DEHP)), benzothiazoles (benzothiazole, 2-(methylthio)-benzothiazol, and 2(3H)-benzothiazolone) and phenol. This study indicated that the presence of considerable amounts of micropollutants in secondary effluent creates the need for suitable advanced treatment before their reuse.

Identification and quantification of bipyridyl dicarboxylic acid isomers by ion mobility spectrometry.

The identification of positional isomers is of interest because different isomers have different chemical or biological functions and applications. The analysis of positional isomers is sometimes challenging since they have similar chemical structures and properties. For example, the analysis of mass cannot identify different positional isomers because they have identical mass-to-charge ratios and show a single mass peak in mass spectrometry. In this study, an efficient and simple qualitative and quantitative analytical method for differentiating 2,2'-bipyridine-3,3'-dicarboxylic acid (3,3'-BDA), 2,2'-bipyridine-4,4'-dicarboxylic acid (4,4'-BDA), and 2,2'-bipyridine-5,5'-dicarboxylic acid (5,5'-BDA) was developed by using ion mobility spectrometry (IMS). The results revealed that the three BDA isomers formed non-covalent complexes with cyclodextrins (CDs) and Mg2+ ions in the gas phase: [ß-CD+3,3'/4,4'/5,5'-BDA+Mg]2+ and [γ-CD+3,3'/4,4'/5,5'-BDA+Mg]2+, which were distinguished by measuring the mobility of the complexes because of their spatial conformational differences. The peak-to-peak resolution (Rp-p) values of the three isomers of [γ-CD+3,3'/4,4'/5,5'-BDA+Mg]2+ reached 2.983 and 2.892, respectively. The conformations of the ternary complexes simulated by the theoretical calculations revealed the different interactions and shapes of the stereoisomers, and the predicted results agreed with the experimental results. Simultaneously, further studies on the collisional dissociation of the ternary complexes revealed that the dissociation energies of the different complex ions varied were different owing to the diverse different conformations. Finally, the relative quantitative analysis of the different isomers in mixed samples was performed and satisfactory linearity results (R2 > 0.99) were obtained. Thus, an effective analytical method was proposed for the identification and quantification of BDA isomers without chemical derivatization, offering a promising approach for the identification of similar derivatives or positional isomers that could be applied in various fields including chemicals and pharmaceuticals.

An efficient convolutional neural network-based diagnosis system for citrus fruit diseases.

Introduction: Fruit diseases have a serious impact on fruit production, causing a significant drop in economic returns from agricultural products. Due to its excellent performance, deep learning is widely used for disease identification and severity diagnosis of crops. This paper focuses on leveraging the high-latitude feature extraction capability of deep convolutional neural networks to improve classification performance. Methods: The proposed neural network is formed by combining the Inception module with the current state-of-the-art EfficientNetV2 for better multi-scale feature extraction and disease identification of citrus fruits. The VGG is used to replace the U-Net backbone to enhance the segmentation performance of the network. Results: Compared to existing networks, the proposed method achieved recognition accuracy of over 95%. In addition, the accuracies of the segmentation models were compared. VGG-U-Net, a network generated by replacing the backbone of U-Net with VGG, is found to have the best segmentation performance with an accuracy of 87.66%. This method is most suitable for diagnosing the severity level of citrus fruit diseases. In the meantime, transfer learning is applied to improve the training cycle of the network model, both in the detection and severity diagnosis phases of the disease. Discussion: The results of the comparison experiments reveal that the proposed method is effective in identifying and diagnosing the severity of citrus fruit diseases identification.

Mass spectrometry-based multimodal approaches for the identification and quantification analysis of microplastics in food matrix.

Background: Microplastics (MPs) and nanoplastics (NPs) have become emerging contaminants worldwide in food matrices. However, analytical approaches for their determination have yet to be standardized. Therefore, a systematic study is urgently needed to highlight the merits of mass spectrometry (MS) based methods for these applications. Purpose: The aim of the study is to review the current status of MS-based multimodal analysis for the determination of MPs in food matrices. Methods: Web of Science and Google Scholar databases were searched and screened until Jan. 2023. Inclusion criteria: "publication years" was set to the last decades, "English" was selected as the "language," and "research area" was set to environmental chemistry, food analysis and polymer science. The keywords were "microplastics," "nanoplastics," "determination," "identification/quantification," and "mass spectrometry." Results: Traditional spectrometry techniques offer good abilities to conduct the multimodal analysis of MPs in terms of color, shape and other morphologies. However, such technologies have some limitations, in particular the relatively high limits of detection. In contrast, MS-based methods supply excellent supplements. In MS-based methods, gas chromatographic-mass spectrometry (GC-MS), and LC-MS/MS were selected as representative methods for determining MPs in the food matrices, while specialized MS methods (i.e., MALDI-ToF MS and ToF-SIMS) were considered to offer great potential in multimodal analysis of MPs especially when interfaced with the imaging systems. Significance: This study will contribute to gaining a deeper insight into the assessment of the exposure levels of MPs in human body, and may help build a bridge between the monitoring studies and the toxicology field.

Quantification of the benzimidazole opioid analog isotonitazene in human hair using liquid chromatography-tandem mass spectrometry.

Benzimidazole opioids were originally developed from the late 1950s to 1970s as analgesics for medical use, although a lot of them could not be approved as licit medicines because of their severe side effects and physical dependence. Such benzimidazole opioid analogs as abused drug, however, have recently been found in illicit drug markets throughout the world. Isotonitazene is one such benzimidazole opioids, whose analgesic potency can be as much as 500 times greater than that of morphine, according to previous animal studies. In line with this potency, a couple of hundred fatalities related to it were reported to date. In this study, a well validated method for the quantification of isotonitazene in human hair samples using liquid chromatography (LC)-tandem mass spectrometry (MS/MS) was established, and could be applied to authentic samples which were seized by the police security bureau. Isotonitazene concentrations in the seized hair averaged 6.11 pg/mg. The LLOQ and LOD of this method were 1.25 and 2.5 pg/mg, respectively; the calibration curve of the substance in hair samples showed a good linearity in the concentration range of 2.5-250 pg/mg (r > 0.999); the extraction recovery rates were 87.3-105% in the tested range; the inter- and intra-day precisions and accuracies (%biases) were not greater than 9.09% for each determination. Isotonitazene in human hair showed good stability at room temperature and under dark storage conditions for 30 days. As for matrix effect in hair samples, moderate ion suppression of target substances could be found. This is the first report for the analysis of isotonitazene in human hair samples.

Quantification of a new recreational drug 2-methoxyqualone in human hair using gas chromatography-tandem mass spectrometry.

A method for identification and quantification of 2-methoxyqualone, an newly emerging quinazolinone derivative recreational drug, in human scalp hair was established using gas chromatography (GC)-tandem mass spectrometry (MS/MS). In this report, authentic cases are presented, in which the suspects were seized by police security bureau; the police in China requested our laboratory to identify and quantify the involved drug(s) of abuse in the hair samples of the suspects. After washing and cryo-grinding the authentic hair samples, the target compound was extracted with methanol, and the solvent layer was evaporated to dryness. The residue was reconstituted in methanol and analyzed by GC-MS/MS. 2-Methoxyqualone concentrations in the hair were between 35.1 and 116 pg/mg. The calibration curve of the substance in hair samples showed a good linearity in the concentration range of 10-1000 pg/mg (r > 0.998); the extraction recovery rate, 88.8-105.6 %; the interday and intraday precisions and accuracies (biases), not greater than 8.9 %. 2-Methoxyqualone in human hair had good stability under three different storage conditions at room (20 °C), refrigerated (4 °C) and frozen (- 20 °C) temperatures for at least 7 days. In the present report, simple and rapid quantification method for 2-methoxyqualone in human scalp hair have been established using GC-MS/MS and it could successfully be applied to authentic forensic toxicological cases. To our knowledge, this is the first report for quantification of 2-methoxyqualone in human hair samples.

Enhancing the Yield of a Lab-on-a-Disk-Based Single-Image Parasite Quantification Device.

The recently proposed single-image parasite quantification (SIMPAQ) platform based on a Lab-on-a-Disc (LOD) device was previously successfully tested in field conditions, demonstrating its efficiency in soil-transmitted helminth (STH) egg detection and analysis on the level delivered by the current state-of-the-art methods. Furthermore, the SIMPAQ provides relatively quick diagnostics and requires small amounts of sample and materials. On the other hand, in a recent related study, it was revealed that the performance of the SIMPAQ method can be limited due to the action of the tangential Euler and Coriolis forces, and the interaction of the moving eggs with the walls of the LOD chamber. Here, we propose a new improved design that allows us to overcome these limitations and enhance the yield of the SIMPAQ LOD device, as demonstrated in experiments with a synthetic particle model system and real parasite eggs. Despite the simplicity, the proposed design modification is demonstrated to allow a substantial improvement in the yield of the SIMPAQ device, i.e., above 90% of parasite eggs and 98% of synthetic model particles were transported to the field of view. The new design proposed here will be further examined in the new generation of SIMPAQ devices within ongoing research on STH egg detection in field conditions.

Benefits of FAIMS to Improve the Proteome Coverage of Deteriorated and/or Cross-Linked TMT 10-Plex FFPE Tissue and Plasma-Derived Exosomes Samples.

The proteome characterization of complex, deteriorated, or cross-linked protein mixtures as paired clinical FFPE or exosome samples isolated from low plasma volumes (250 µL) might be a challenge. In this work, we aimed at investigating the benefits of FAIMS technology coupled to the Orbitrap Exploris 480 mass spectrometer for the TMT quantitative proteomics analyses of these complex samples in comparison to the analysis of protein extracts from cells, frozen tissue, and exosomes isolated from large volume plasma samples (3 mL). TMT experiments were performed using a two-hour gradient LC-MS/MS with or without FAIMS and two compensation voltages (CV = -45 and CV = -60). In the TMT experiments of cells, frozen tissue, or exosomes isolated from large plasma volumes (3 mL) with FAIMS, a limited increase in the number of identified and quantified proteins accompanied by a decrease in the number of peptides identified and quantified was observed. However, we demonstrated here a noticeable improvement (>100%) in the number of peptide and protein identifications and quantifications for the plasma exosomes isolated from low plasma volumes (250 µL) and FFPE tissue samples in TMT experiments with FAIMS in comparison to the LC-MS/MS analysis without FAIMS. Our results highlight the potential of mass spectrometry analyses with FAIMS to increase the depth into the proteome of complex samples derived from deteriorated, cross-linked samples and/or those where the material was scarce, such as FFPE and plasma-derived exosomes from low plasma volumes (250 µL), which might aid in the characterization of their proteome and proteoforms and in the identification of dysregulated proteins that could be used as biomarkers.

Novel automated identification and quantification database using liquid chromatography quadrupole time-of-flight mass spectrometry for quick, comprehensive, cheap and extendable organic micro-pollutant analysis in environmental systems.

In order to protect human health and the environment, highly efficient, low-cost, labor-saving, and green analysis of toxic chemicals are urgently required. To achieve this objective, we have developed a novel database-based automated identification and quantification system (AIQS) using LC-QTOF-MS. Since the AIQS uses retention times (RTs), exact MS and MS-MS spectra, and calibration curves of 484 chemicals registered in the database instead of the use of standards, the targets can be determined with low-cost in a short time. The AIQS uses Sequential Window Acquisition of All Theoretical Fragment-ion Spectra as an acquisition method by which we can obtain accurate MS and MS-MS spectra of all detectable substances in a sample with minimal interference from co-eluted peaks. Identification is certainly done using RTs, mass error, ion ratios (a precursor to two product ions), and accurate MS and MS-MS spectra. Consequently, the chance of misidentification is very low even in dirty samples. To examine the accuracy of the AIQS, two collaborative tests were conducted. The first test used 208 pesticide standards at two concentrations (10 and 100 ng mL-1) using 7 instruments, and showed that average trueness was 106 and 95.2%, respectively, with relative standard deviations of 90% of the test compounds below 30%. The second collaborative study involved 5 laboratories carrying out recovery tests on 200 pesticides using 10 river waters. The average recovery was 71.6%; this was 15% lower than that using purified water probably due to the matrix effects. The average relative standard deviation was 30% worse than that of measurement of the standards. Both the recovery and reproducibility, however, satisfied the criteria of Analytical Method Validity Guidelines, Ministry of Health, Labour and Welfare, Japan. Instrument detection limits of 96% of the registered compounds are below 10 pg. The AIQS allows for easy addition of new substances and retrospective analysis after their addition. The results applied to actual samples showed that the AIQS has sufficient identification and quantification performance as a target screening method for a large number of substances in environmental samples.