Application Of Spectrometry Research Articles

Molecular insight into algae-derived dissolved organic matters via Fourier-transform ion cyclotron resonance mass spectrometry: Effects of pretreatment methods and electrospray ionization modes

The release of algae-derived dissolved organic matter (ADOM) significantly increased in serious eutrophication waters, posing great threats to drinking water safety. Thus, the molecular composition decipherment is urgently in need. However, due to unsatisfactory pretreatment and ionization effects, the application of Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) on ADOM was limited. Therefore, the effects of pretreatment methods (cartridge type and loading) during solid-phase extraction (SPE) and electrospray ionization (ESI) modes with FT-ICR-MS on the molecular composition of ADOM were evaluated. The results showed compared with silica-based octadecyl (C18) cartridge, styrene-divinylbenzene polymer (PPL) cartridge exhibited higher recovery efficiency and retained more saturated and oxygenated compounds, such as carbohydrate-like and tannin-like. Furthermore, the recovery efficiency decreased with increasing loading, and hydrophilic and high-oxygenated carbohydrate-like and tannin-like were continuously replaced by hydrophobic and low-oxygenated aliphatic and aromatic compounds. Moreover, compared to negative ESI mode, the addition of positive ESI mode increased the molecular chemodiversity, especially more lipid-like and protein-like compounds. Thus, we proposed < 1:500 DOC/PPL mass ratio during SPE and dual ESI modes coupled with FT-ICR-MS could identify ADOM molecules more comprehensively. This work contributes to more comprehensive understanding of the molecular composition of ADOM and provides more references for pretreatment and characterization strategies of severely eutrophic waters.

Evaluation of photocathode materials in combination with commercial fiber-coupled UV photon sources as a compact electron source in mass spectrometry

Abstract The design of a compact electron source for mass spectrometry applications based on commercially available plug-and-play light sources and sturdy materials is presented, and its performance of photo-electron production is evaluated. We report quantum yields ranging between 1 – 2.5 x10-5 for aluminum, 9 x10-8 – 3 x10-6 for stainless steel, 1 – 2.2 x10-6 for molybdenum, 6.3 x10-7 – 5.1 x10-6 for tantalum, and 1.4 – 2.1 x10-6 for titanium, depending on the wavelength range of the irradiation source. In terms of quantum yield, the deuterium lamp provided better results compared to the two UV LEDs for all metals. However, due to their higher optical output power, the LEDs nevertheless yield a higher photoelectron current for all metals except for stainless steel. The measured photo-currents ranged from 1 – 2 nA for aluminum to 0.01 nA for Stainless Steel samples.

Comparative Investigation of Aroma-Active Volatiles in ("Ruixue", "Liangzhi", "Crystal Fuji," and "Guifei") Apples by Application of Gas Chromatography-Mass Spectrometry-Olfactometry (GC-MS-O) and Two-Dimensional Gas Chromatography-Quadrupole Mass Spectrometry (GC × GC-qMS) Coupled with Sensory Molecular Science.

Aroma dramatically impacts the overall flavor profiles and consumer acceptance; therefore, it is necessary to conduct a comprehensive analysis of the aroma characteristics of apples. In this study, the aroma differences among four popular apple varieties ("Ruixue", "Liangzhi", "Crystal Fuji," and "Guifei") were compared using two extraction methods (headspace-solid phase microextraction, and solvent-assisted flavor evaporation) coupled with gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS). A total of 82 odorants were identified via GC-MS-O, and 143 volatiles were identified by GC× GC-qMS. Among them, 41 key aroma-active compounds (butanal, ethyl acetate, 3-methylbutanal, methyl butanoate, 2-methylpropyl acetate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, butyl acetate, hexanal, 2-methylbutyl acetate, 1-butanol, 2-methylpropyl butanoate, 3-methylbutyl acetate, (E)-2-hexenal, butyl butanoate, butyl 2-methylbutanoate, hexyl acetate, hexyl butanoate, hexyl, 2-methylbutanoate, 1-octen-3-ol, 3-methylthiopropanol, 1,3-octanediol, linalyl acetate, and so on) with high odor activity values (OAVs) and AI value (odor activity values ≥1 or aroma intensity ≥3) were identified. Partial least-squares-discriminant analysis showed that Ruixue exhibited a high "fruity" note, Guifei and Crystal Fuji had the greatest "wood," "floral," and "sweet" notes, while Liangzhi presented a significant "green" note. This study provided flavor chemistry support for the apple quality control and production.

Application of liquid chromatography-mass spectrometry for the determination of semaglutide in human serum in clinical pharmacokinetic studies

Introduction. Semaglutide preparations are an important therapeutic option for patients suffering from type 2 diabetes mellitus and obesity due to their high efficacy and the expected increase in the prevalence of these diseases. Consequently, there is a growing need for the development of domestic analogs of semaglutide requiring bioequivalence studies. This study proposes the use of high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) as an alternative to the widely used immunoassay for the quantitative determination of semaglutide in human serum.Aim. To develop and validate a method for the quantitative determination of semaglutide in human serum using HPLC-MS/MS.Materials and methods. Serum sample preparation was based on protein precipitation using an acetonitrile-methanol mixture. Liraglutide was selected as the internal standard. The mobile phase consisted of 0.3% formic acid in water and acetonitrile. The stationary phase was represented by a Phenomenex Kinetex C18 chromatographic column 100×3.0 mm, 5 μm, 100 Å. Ionization of semaglutide and liraglutide was performed in positive electrospray mode. Detection was carried out in multiple reaction monitoring mode (MRM).Results. The method demonstrated high accuracy and precision, with relative error and relative standard deviation values of less than 15% across all quality control levels. The confirmed analytical ranges of the method were 0.50–200.00 ng/mL and 1.00–800.00 ng/mL. Over 3.400 volunteer samples were analyzed as part of the studies. Compared to the ELISA method, the proposed method provides higher selectivity and reproducibility of measurements.Conclusions. The method has been developed that provides reproducible quantitative determination of semaglutide in human blood serum. The method was validated in accordance with EAEU requirements and was successfully applied in bioequivalence studies of semaglutide GP40331 (GEROPHARM LLC, Russia). The method is suitable for conducting pharmacokinetic studies of other semaglutide preparations.

Validation and application of quick polar pesticide (QuPPe) extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to analyze perchlorate in vegetables from Mexico

Perchlorate is a contaminant and endocrine disruptor present in vegetables. To address the lack of information on this problem in Mexico, we developed an analytical method to quantify perchlorate in commonly consumed vegetables based on quick polar pesticide (QuPPe) extraction and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The method was validated through the parameters of selectivity, accuracy, precision, linearity, limit of detection (LOD), and limit of quantification (LOQ) according to SANTE guidelines. The developed method exhibited a linear range of 0.005–0.100 mg/kg with LOD and LOQ values of 0.001 and 0.003 mg/kg, respectively. Recovery in a fortified tomato matrix was 96.85 ± 12.90% with a coefficient of variation (CV) of 11.55 ± 0.84%. The method was applied to analyze 31 vegetable samples collected from different regions in Mexico. Perchlorate concentrations ranged from not detected (ND) to 0.016 mg/kg, fresh weight. This method generates robust scientific evidence to implement and strengthen perchlorate monitoring programs for food matrices, supporting efforts to regulate this analyte in Mexico.

Advances in the application of liquid chromatography tandem mass spectrometry for therapeutic drug monitoring

Therapeutic drug monitoring is a good interpretation of personalized medicine, which helps to improve the safety and effectiveness of patient medication. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has gradually been widely accepted by clinical laboratories due to its characteristics of specificity, sensitivity, and flexibility in method development. This article introduces the importance and analytical techniques for therapeutic drug monitoring, describes the application and development of liquid chromatography tandem mass spectrometry for therapeutic drug monitoring, new advances in the detection of different drug types and sample types, and challenges in automation, convenience, and standardization.

Potential and application of tandem mass spectrometry (MS/MS) in the analysis and identification of novel bacteriocins: a review

SummaryBacteriocins are antimicrobial peptides synthesised ribosomally by Gram‐positive or Gram‐negative bacteria to gain a competitive advantage. The majority of bacteriocins are derived from Gram‐positive bacteria, with lactic acid bacteria being the most common source. Because they are considered ‘natural’, there is currently significant development of bacteriocins for application as food preservative agents. As a preservative agent, bacteriocin activity is highly dependent on purity, down to the amino acid profile and sequence. Therefore, bacteriocin identification is important. Currently, MS is a cutting‐edge tool in bacteriocin identification. This method has high selectivity, sensitivity and resolution. To the best of our knowledge, systematic reviews focusing on the application of MS for bacteriocin identification are currently limited. In light of this, the objective of this study is to provide a comprehensive review and summary of MS technologies in bacteriocin research, with a particular focus on the discovery and characterisation of novel sources of bacteriocin. Additionally, studies related to the discovery of bacteriocins from various sources, their role as antimicrobial agents, and their synthesis are emphasised. Thus, this study presents a comprehensive analysis of the advantages, limitations, and future perspectives of the methods employed.

Advances in the application of ion chromatography-mass spectrometry in the fields of life and health

Ion chromatography is a technique commonly used to separate strongly polar and ionizable substances; it can be used to separate, identify, and quantify ionizable compounds in complex samples when coupled with mass spectrometry, and is currently being used in the application of food analysis, drug analysis, metabolomics and clinical poisoning analysis. Herein, we review the development of ion chromatography-mass spectrometry (IC-MS), its progress over the past 20 years, and future trends in the abovementioned areas. The IC-MS research progress and applications for the determination of inorganic anions, organic acids, polar pesticides, biogenic amines, and sugars in the food field are discussed. Drug analysis applications are discussed mainly in relation to the analysis of drug impurities, identifying drug degradation products, and determination of plasma concentration, while the separation and analysis of strongly polar metabolites, such as organic acids, sugar phosphates, and nucleotides in biological matrices are discussed in relation to metabolomics. Advances in the analysis of strongly polar or ionizable toxic compounds, such as alkyl methylphosphonic acid, methylphosphonic acid, glyphosate, 3-nitropropionic acid, and indandione rodenticides, are mainly discussed in clinical poisoning analysis field. This paper is expected to become a useful reference for the further expansion and application of IC-MS in the life and health fields.

Application of mass spectrometry in single-cell metabolomics

Application of mass spectrometry in single-cell metabolomics

Design, Synthesis, Biological Evaluation and Molecular Docking Studies of a New Series of Maleimide Derivatives.

A series of novel maleimide derivatives were synthesized, with various heterocyclic compounds serving as side chains in the synthesis process. The structural characteristics of these compounds were elucidated through the application of 1H-NMR spectroscopy, 13C-NMR (APT) spectroscopy, and high-resolution mass spectrometry (HRMS). The anti-cancer potential of these compounds was subsequently assessed in vitro, utilizing two distinct breast cancer cell lines, namely MDA-MB-231 and MCF-7, via MTT assay. Among the 12 newly synthesized compounds, 4 a, 4 b, 4 c, 4 d, 5 a, 5 b, 5 c and 5 d were determined to show the most promising anti-cancer activity against both breast cancer cell lines. Moreover, the morphological changes induced in the cells following a 24-hour incubation period with these compounds were observed using light microscopy. Additionally, molecular dynamics simulations were conducted to assess the stability of the bound conformations of the compounds to the target protein GSK-3β as obtained through molecular docking calculations.

Application of photothermal beam deflection spectrometry for non-destructive evaluation of advanced materials: a state-of-the-art review

Abstract The progress made in lasers and data acquisition systems has paved the way for innovative non-destructive evaluation methods based on the photothermal phenomenon. Beam deflection spectrometry (BDS) is a photothermal spectroscopic technique that offers ultra-sensitivity, high signal-to-noise ratios, and reduced sample preparation requirements. These advantages provide precise assessment of advanced material (AM) properties. This review presents a comprehensive in-depth analysis, thus helping researchers to understand the potential and future perspectives of BDS along with the theory, instrumentation, and application supported by the literature data. The objective of this review is also to present the possibilities of BDS in the characterization of AMs, including organic, inorganic, and hybrid organic–inorganic materials in the form of thin films, coatings, composites, and nanomaterials.

Application of Mass Spectrometry for Analysis of Nucleobases, Nucleosides and Nucleotides in Tea and Selected Herbs: A Critical Review of the Mass Spectrometric Data.

The main and most commonly known biological function of nucleobases, nucleosides, and nucleotides is usually associated with the fact that they are the building blocks of nucleic acids. However, these compounds also belong to plant secondary metabolites, although in that role they have attracted less attention than the others, e.g., terpenes, phenolics, or alkaloids. The former compounds are also important constituents of the human diet, e.g., as ingredients of tea and herbs, endowing them with specific taste qualities and pharmacological activities. Liquid chromatography-mass spectrometry seems to be the most important analytical method that permits the identification and determination of nucleobases, nucleosides, and nucleotides, along with the other metabolites. The main goal of this review is to discuss in detail the aspects of mass spectrometric detection of nucleobases, nucleosides, and nucleotides in tea and selected herbs. An important conclusion is that the identification of the compounds of interest should be performed not only on the basis of [M + H]+/[M - H]- ions but should also be confirmed by the respective product ions; however, as discussed in detail in this review, it may sometimes be problematic. It also clear that all difficulties that may be encountered when analyzing plant material are caused by the complexity of the analyzed samples and the need to analyze different classes of compounds, and this review absolutely does not debase any of the mentioned papers.

Application of electrospray triple quadrupole mass spectrometry in assessing thalassemia in a population.

Thalassemia is widely prevalent in Asian countries and the Middle East region of the world. While the prevalence of α thal is around 5-20% in the population, the incidence of β thal is around 3-4%. The available data on thalassemia in Indians is based on chromatographic or electrophoretic techniques. The present study demonstrates the utility of mass spectrometry in detecting thalassemia in a small, healthy population from Tiptur, Karnataka. The study included a population of 315 individuals, spanning both children and adults, with ages ranging from 4 to 76 years. EDTA whole blood was collected after obtaining their written consent. The intensities of various globin chains were measured using a triple quadrupole mass spectrometer. The ratio of the peak areas of globin chains (α/β, δ/β (%)) served as biomarkers to detect thalassemia. Thirty random samples of α thalassemia were analyzed using GapPCR. The prevalence of a thal is 21.65% (68/314) based on α/β (< =0.8) and the prevalence of β thal is 3.8% (12/314) based on δ/β (%) (> =11.0). GapPCR detected three heteromutants of α deletion, one mutation in the HBA1 gene, and one a triplication (16.7%, 5/30). One sample was excluded from the analysis due to the presence of a variant. The utility of mass spectrometry for screening thalassemia in a population is demonstrated. The higher occurrence of α-thalassemia in the studied population underscores the importance of screening for thalassemia in regions with reportedly high prevalence rates.

Mass Spectrometry Advancements and Applications for Biomarker Discovery, Diagnostic Innovations, and Personalized Medicine.

Mass spectrometry (MS) has revolutionized clinical chemistry, offering unparalleled capabilities for biomolecule analysis. This review explores the growing significance of mass spectrometry (MS), particularly when coupled with liquid chromatography (LC), in identifying disease biomarkers and quantifying biomolecules for diagnostic and prognostic purposes. The unique advantages of MS in accurately identifying and quantifying diverse molecules have positioned it as a cornerstone in personalized-medicine advancement. MS-based technologies have transformed precision medicine, enabling a comprehensive understanding of disease mechanisms and patient-specific treatment responses. LC-MS has shown exceptional utility in analyzing complex biological matrices, while high-resolution MS has expanded analytical capabilities, allowing the detection of low-abundance molecules and the elucidation of complex biological pathways. The integration of MS with other techniques, such as ion mobility spectrometry, has opened new avenues for biomarker discovery and validation. As we progress toward precision medicine, MS-based technologies will be crucial in addressing the challenges of individualized patient care, driving innovations in disease diagnosis, prognosis, and treatment strategies.

Discrimination of coal geographical origins through HS-GC-IMS assisted with machine learning algorithms in larceny case

The process of globalization and industrialization has resulted in a rise in the theft of coal and other related products, thereby becoming a focal point for forensic science. This situation has engendered an escalated demand for effective detection and monitoring technologies. The precise identification of coal trace evidence presents a challenge with current methods, owing to its minute quantity, fine texture, and intricate composition. In this study, we integrated machine learning with the identification of volatiles to accurately differentiate coal geographical origins through the application of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). The topographic distribution of volatiles in coals was visually depicted to elucidate the subtle distinctions through spectra and fingerprint analysis. Additionally, four supervised machine learning algorithms were developed to quantitatively predict the geographical origins of natural coals utilizing the HS-GC-IMS dataset, and these were subsequently compared with unsupervised models. Remarkable volatile compounds were identified through the quantitative analysis and optimal Random Forest model, which offered a rapid readout and achieved an average accuracy of 100 % in coal identification. Our findings indicate that the integration of HS-GC-IMS and machine learning is anticipated to enhance the efficiency and accuracy of coal geographical traceability, thereby providing a foundation for litigation and trials.

Identifying and Quantifying Relative Concentrations of Epimers in Mixtures via Cyclic Ion Mobility Mass Spectrometry: Dexamethasone and Betamethasone as a Case Study.

Epimers can show different biological activities and different pharmacological behaviors; therefore, their separation and analysis are crucial in the drug development process. Due to their similar chemical and physical properties, separation of epimers is challenging. This study demonstrates the application of cyclic ion mobility-mass spectrometry to separate, identify, and quantify dexamethasone and betamethasone in a binary mixture. Cyclic IMS separation of the isolated protonated dimer resulted in three peaks: dexamethasone homodimer, betamethasone homodimer, and their heterodimer. Besides providing improved separation over the protonated monomer, the presence of a heterodimer peak provides additional confirmation of an isomeric mixture. We identified the dexamethasone and betamethasone homodimer peaks by infusing pure solutions of each epimer and measuring each pure homodimer's arrival time. The measured peak areas indicated that the heterodimer is formed at twice the rate of each homodimer and that dexamethasone and betamethasone contribute equally to the heterodimer signal. Using this observation, we could accurately calculate the relative concentrations of each epimer by adding half of the heterodimer peak area to each homodimer peak area. These findings enable the identification and quantification of dexamethasone and betamethasone based on the arrival time distributions of their protonated dimers. This is the first demonstration of accurate relative quantification of epimers by separating charged dimers in the gas phase.

LEAD-LEAD DATING REVEALS PERMIAN REMOBILIZATION OF NIOBIUM MINERALIZATION AT BAYAN OBO

Abstract The Bayan Obo deposit hosted by the H8 unit is a world-class rare earth element (REE) deposit with considerable niobium (Nb) and iron (Fe). Permian granites are widely exposed in the mining area and have a close spatial association with the Nb mineralization. Whether the granites contributed Nb or only remobilized existing mineralization is important for understanding the controls of ore formation. Previous studies have mostly focused on the REEs, whereas research on Nb has been limited. This is due mainly to the difficulty of accurately determining the age of the Nb mineralization because of the fine-grained and texturally complex nature of the Nb-bearing minerals and their exceptionally low U content. Although microbeam techniques show promise in tackling the aforementioned challenges, their application is hampered by matrix effects caused by the diverse composition of Nb-bearing minerals. Here we report the application of a high-precision secondary ion mass spectrometry (SIMS) Pb-Pb isochron approach that enables young samples (i.e., &amp;lt;500 Ma) to be dated without matrix-matched reference materials. A variety of Nb-bearing minerals from eastern Bayan Obo were analyzed, yielding Pb-Pb isochron ages of 276 ± 10 Ma (pyrochlore, 394–6,864 ppm U in the rim and 6,563–19,858 ppm in the core), 277 ± 36 Ma (fersmite, 18–61 ppm U; fergusonite-Ce, 45–95 ppm U), and 257 ± 46 Ma (aeschynite, 342–1,006 ppm U). In combination with the deposit geology and petrographic observations, these ages link the Nb mineralization to ~270 Ma granites. As these granites are not particularly rich in Nb, skarn formation during granite emplacement is interpreted to have remobilized the existing Nb mineralization, which increased the grain size of the Nb-bearing minerals—a key factor facilitating their extraction. Our study shows that high-precision SIMS Pb-Pb analysis holds promise for directly dating mineralization without matrix-matched reference materials. It also emphasizes the need to consider the role of the Nb remobilization at Bayan Obo and elsewhere.

Clostridium butyricum Prevents Diarrhea Incidence in Weaned Piglets Induced by Escherichia coli K88 through Rectal Bacteria-Host Metabolic Cross-Talk.

This study aimed to evaluate the effects of Clostridium butyricum (C. butyricum) on the prevention of the diarrhea rates and growth performances of weaned piglets induced by Escherichia coli K88 (E. coli K88). Twenty-four weaned piglets (6.92 ± 0.11 kg) were randomly assigned to one of three treatment groups for a period of 21 days. Each group consisted of eight pigs, with each pig being housed in an individual pen. Group I received the control diet along with normal saline, Group II received the control diet along with E. coli K88, and Group III received the control diet supplemented with 5 × 108 CFU/kg of C. butyricum and E. coli K88. We examined alterations in rectal microbiota and metabolites, analyzed the incidence of diarrhea, and investigated the interactions between microbiota and metabolites through the application of Illumina MiSeq sequencing and liquid chromatography-mass spectrometry. The results showed that, from days 14 to 21, the diarrhea incidence in Group III decreased significantly by 83.29% compared to Group II (p < 0.05). Over the entire experimental duration, the average daily feed intake of Group III decreased significantly by 11.13% compared to Group I (p < 0.05), while the diarrhea incidence in Group III decreased by 71.46% compared to Group II (p < 0.05). The predominant microbial flora in the rectum consisted of Firmicutes (57.32%), Bacteroidetes (41.03%), and Proteobacteria (0.66%). Administering E. coli K88 orally can elevate the relative abundance of Megasphaera (p < 0.05). Conversely, the supplementation of C. butyricum in the diet reduced the relative abundance of Megasphaera (p < 0.05), while increasing the relative abundance of unclassified_f_Lachnospiraceae (p < 0.05). Rectal metabolomics analysis revealed that supplementing C. butyricum in the feed significantly altered the amino acids and fatty acids of the piglets infected with E. coli K88 (p < 0.05). The correlation analysis showed that the occurrence of diarrhea was inversely related to adipic acid (p < 0.05) and positively associated with (5-hydroxyindol-3-YL) acetic acid and L-aspartic acid (p < 0.05). Prevotella_1 exhibited a negative correlation with octadecanoic acid (p < 0.05). Prevotellaceae_UCG-005 showed a negative correlation with (5-hydroxyindol-3-YL) acetic acid (p < 0.05). The findings from this research study aid in probiotic development and the enhancement of healthy growth in weaned piglets.

Forensic application of sandpaper spray ionization mass spectrometry (SPS-MS): Direct analysis of solid pharmaceutical formulations and edible cannabis products.

In this work, we employed a new ambient ionization mass spectrometry technique, sandpaper spray mass spectrometry (SPS-MS), as an efficient tool to analyze pills and tablets of pharmaceutical formulations. The following samples were analyzed: regulators of blood pressure, cholesterol, and diabetes, and drugs for the treatment of erectile dysfunction (ED). Additionally, a hard candy of Cannabis sativa containing Δ9-tetrahydrocannabinol (Δ9-THC) and its related isomer cannabidiol (CBD) was also evaluated. The surfaces of the samples, without any prior treatment, were sanded onto triangular-cut sandpaper, and full MS scans (and MS/MS) were acquired in both positive and negative ionization modes. SPS-MS (and MS/MS) allowed for prompt detection of the active pharmaceutical ingredients (APIs) in each formulation. Other components of the formulations, added as excipients, were also tentatively identified. The results described herein indicate that the SPS-MS technique can be applied to fast screening of pills and tablets being potentially used as an efficient tool to detect counterfeit pharmaceutical and illicit products, a current issue of increasing concern.

Application of airborne gamma-ray spectrometry in geological lithology mapping—a case study of a region in the Qinling Mountains, China

Application of airborne gamma-ray spectrometry in geological lithology mapping—a case study of a region in the Qinling Mountains, China