Rapid Communications in Mass Spectrometry最新文献

{"title":"Rapid Determination of 15 Herbicides in Blood and Soil by Direct Analysis in Real Time-Tandem Mass Spectrometry","authors":"Zhou Yuan,&nbsp;Zhang Ying,&nbsp;Hou Xiaolong,&nbsp;Xue Chenyu,&nbsp;Zhang Wenfang,&nbsp;Qiao Jing,&nbsp;Liu Hua,&nbsp;Zhang Wenjin,&nbsp;Guo Yizhu","doi":"10.1002/rcm.10023","DOIUrl":"https://doi.org/10.1002/rcm.10023","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The rampant abuse of herbicides in agricultural practices has resulted in frequent incidents of both unintended and deliberate poisoning, posing dual threats to ecosystems and human health. This underscores an urgent need for efficient herbicide detection methods.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A direct analysis in real time coupled with tandem mass spectrometry (DART-MS/MS) method was developed for the simultaneous detection of 15 herbicides in blood and soil. Systematic optimization of mass spectrometric parameters established optimal detection conditions in multiple reaction monitoring (MRM) mode, with the ion source temperature set at 450°C. Following liquid-liquid extraction of blood or soil samples, the processed supernatant was analyzed directly.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The method demonstrated excellent linearity (R^² ≥ 0.99) across a wide concentration range. Sensitivity was validated with limits of detection (LODs) of 1–20 ng/mL in blood and 1–10 ng/g in soil, and limits of quantification (LOQs) of 1–50 ng/mL in blood and 1–20 ng/g in soil. Satisfactory recovery rates and controlled matrix effects met toxicological requirements. In 2024, the method was successfully applied to four real cases of herbicide poisoning.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study established the first DART-MS/MS method for simultaneous analysis of 15 herbicides in biological (blood) and environmental (soil) matrices. The complete analytical workflow required only 20 minutes from sample preparation to detection, significantly advancing forensic applications of DART-MS/MSwhile providing a reliable technical solution for herbicide screening in forensic investigations.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive Two-Dimensional Gas Chromatography–Mass Spectrometry for the Analysis of Atmospheric Particulate Matter","authors":"Jingying Ma,&nbsp;Yufu Han,&nbsp;Jinfeng Ge,&nbsp;Ling Wen,&nbsp;Chao Ma,&nbsp;Yulin Qi,&nbsp;Dietrich A. Volmer","doi":"10.1002/rcm.10034","DOIUrl":"https://doi.org/10.1002/rcm.10034","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Atmospheric particulate matter (PM) is a complex mixture with a wide range of sources, but only a limited proportion can be identified by existing analytical techniques. Comprehensive two-dimensional gas chromatography–mass spectrometry (GC × GC-MS) couples the advantages on high resolution, sensitivity, and peak capacity on gas chromatography, together with the high mass accuracy and acquisition frequency of time-of-flight mass spectrometry (TOFMS). GC × GC-MS has been gradually applied on the analysis of environmental organic pollutants.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Aims</h3>\u0000 \u0000 <p>This review introduces the principles of GC × GC together with MS and discusses its application on organic compounds in atmospheric PM in the last two decades, so as to provide an outlook on the future trends of GC × GC-MS in this research frontiers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>The review synthesizes findings on the application of GC × GC-MS for analyzing organic pollutants in PM, covering its operational principles and the coupling with TOFMS to enhance mass accuracy and acquisition speed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>GC × GC-MS has significantly improved the identification of PM-associated organic compounds by offering superior separation, peak capacity, and detection sensitivity. The technique has enabled the discovery of previously unresolvable compounds and enhanced source apportionment of PM.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>Despite its analytical advantages, the widespread application of GC × GC-MS in atmospheric studies is hindered by challenges such as complex data processing, instrument cost, and standardization issues.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>GC × GC-MS offers superior separation and identification of complex pollutants, making it invaluable for environmental analysis and applications. Emerging technologies, such as machine learning, will enhance its analytical capabilities and broaden its future applications.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 13","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Matrix Effects in SIMS Using Gaussian Process Regression: The Case of Olivine Mg Isotope Microanalysis","authors":"Keita Itano,&nbsp;Kohei Fukuda,&nbsp;Noriko T. Kita,&nbsp;Kenta Ueki,&nbsp;Tatsu Kuwatani,&nbsp;Shotaro Akaho","doi":"10.1002/rcm.10038","DOIUrl":"https://doi.org/10.1002/rcm.10038","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Matrix effects by secondary ion mass spectrometry (SIMS) are empirically corrected by calibration using matrix-matched reference materials. However, conventional parametric regression cannot estimate the prediction uncertainty to account for the difference in compositions of new data and reference materials. Applying Gaussian process regression (GPR), a nonparametric probabilistic method, enables the correction for matrix effect while providing quantitative prediction uncertainty.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We developed GPR models for estimating instrumental mass fractionation (IMF). Magnesium isotope dataset of 17 olivine reference materials was used as training data, and the developed model was applied to another data set of extraterrestrial olivines.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The GPR model using FeO/MgO, CaO/MgO, Cr₂O₃/MgO, and MnO/MgO achieved the higher prediction accuracy of IMF (<i>R</i>² = 0.98) than a previous study. We found that minor elements in olivine, such as Ca, Cr, and Mn, independently affected the matrix effect. We also demonstrated the effectiveness of this method for extraterrestrial materials.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We concluded that GPR is a powerful approach for correcting the SIMS matrix effect, especially when minor elements impact the matrix effect. This approach can be applied to other trace element and isotope analyses of solid-solution minerals.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 13","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovering Novel Short- and Medium-Chain Esters of Hydroxy Fatty Acids in Human Fecal Samples Using Untargeted Liquid Chromatography/Mass Spectrometry","authors":"Jayashankar Jayaprakash,&nbsp;Divyavani Gowda,&nbsp;Rachana M. Gangadhara,&nbsp;Shalini Jain,&nbsp;Hariom Yadav,&nbsp;Siddabasave Gowda B. Gowda,&nbsp;Shu-Ping Hui","doi":"10.1002/rcm.10032","DOIUrl":"https://doi.org/10.1002/rcm.10032","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Exploring novel metabolites produced by host gut microbiome communication is crucial for understanding their roles in various disease pathologies. We previously uncovered a novel class of lipids, short-chain fatty acid esters of hydroxy fatty acids (SFAHFAs), in mouse fecal samples and demonstrated their promising physiological functions in mammals. However, the discovery of SFAHFAs in human samples remains unexplored.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This study aimed to analyze the SFAHFAs and their structural analogs in human fecal samples using liquid chromatography/mass spectrometry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We identified 26 isomeric lipid species, including SFAHFAs and novel medium-chain fatty acid esters of hydroxy fatty acids (MFAHFAs). The detected SFAHFAs and MFAHFAs were characterized by accurate mass measurements using MSⁿ analysis. The results were validated by matching the mass spectral fragmentation and retention time with authentic standards. Two new MFAHFAs, enanthic acid and caprylic acid esters of long-chain hydroxy fatty acids (C24 and C26), were detected and characterized for the first time in human fecal samples. Among the 26 isomeric lipid species, SFAHFA 2:0/24:0 or 4:0/22:0 and SFAHFA 2:0/24:1 were most abundant among the saturated and unsaturated SFAHFAs, respectively.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study offers the first insights into detecting and characterizing novel gut microbial lipids in human fecal samples. Further investigations are essential to recognize the metabolism and function of these lipids in the human gut.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid Determination of Isotopic Purity of Stable Isotope (D, 15N, or 13C)-Labeled Organic Compounds by Electrospray Ionization-High-Resolution Mass Spectrometry","authors":"Chenlong Liang,&nbsp;Lin Ling,&nbsp;Hao-Yang Wang","doi":"10.1002/rcm.10031","DOIUrl":"https://doi.org/10.1002/rcm.10031","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Stable isotope-labeled organic compounds, containing D, ¹⁵N, or ¹³C, have widespread applications in chemistry, biology, environmental science, and agriculture. However, the isotopic purity calculations for these labeled organic compounds are usually complicated, especially in mixed isotopes-labeled scenarios. Herein, the electrospray ionization-high-resolution mass spectrometry (ESI-HRMS) was applied to determine the isotopic purity for stable isotope-labeled organic compounds, containing D, ¹⁵N, or ¹³C.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The representative isotopolog ion with its specific molecular formula was proposed to represent various labeled states. The isotopic purity was calculated using the corrected intensities of representative isotopolog ions by removing the natural isotopic contributions from preceding peaks. A unified equation has been proposed for the calculation of isotopic purity for various labeled situations including D, ¹⁵N, or ¹³C.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Several case studies were presented and our calculated isotopic purities were all consistent with the isotopic purities provided in the certificate. In-source CID method was applied for the labeled compound (molecular weight &gt; 400 u), when the maximum resolution setting was insufficient to differentiate isobaric isotopolog ions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Finally, a workflow with a Python calculation program was summarized for determinations of the isotopic purity for mono isotope-labeled or mixed isotopes-labeled organic compounds, involving D, ¹⁵N, or ¹³C, by using ESI-HRMS to assign the representative isotopolog ions with accurate mass and excluding the isobar interference.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Mass Spectrometry Fragmentation Patterns Under Electron-Activated Dissociation (EAD) for Rapid Structure Identification of Nitazene Analogs","authors":"Cui-mei Liu,&nbsp;Bo-yu Huang,&nbsp;Zhen-dong Hua,&nbsp;Wei Jia,&nbsp;Li Zhi-yu","doi":"10.1002/rcm.10030","DOIUrl":"https://doi.org/10.1002/rcm.10030","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationate</h3>\u0000 \u0000 <p>The emergence of synthetic opioids represents a complex and concerning development in the field of new psychoactive substances (NPSs). Nitazene analogs, also known as nitazenes or 2-benzylbenzimidazole derivatives, represent a recently emerging and popular subgroup of opioid receptor agonists. This study's streamlined approach aims to facilitate rapid and accurate structural elucidation of emerging nitazene analogs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>Ultra high-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UHPLC-QTOF-MS) with positive electrospray ionization (ESI) was employed to characterize 11 nitazene analogs. The mass spectrometry fragmentation pathways of the characteristic fragment ions under electron-activated dissociation (EAD) mode for nitazene analogs were determined from the high-resolution MS data.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In the MS¹ spectra under ESI, single-charge protonated molecular ion [M + H]⁺ and double charge ion [M + 2H]²⁺ were detected. The characteristic product ions in the MS² spectra under the EAD mode were double charged free radical fragment ions [M + H]^•2+, which were produced through the removal of one electron from the protonated molecular ions, alkyl amino side chain fragment ions, benzyl side chain fragment ions, methylene amino ions, and fragment ions formed by loss of the alkyl side chain from the protonated molecular ions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The fragmentation pathways of the main fragment ions were elucidated based on the EAD-MS² spectra. Based on the summarized mass spectrometry characteristics of nitazene analogs, a flowchart was developed to guide the structure prediction of novel nitazene derivatives encountered in forensic casework. EAD was recognized as a perfect technique for accurate structure prediction and identification of new emerging nitazene analogs.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143690140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strategies for Reducing the Homogenization Phenomenon in the Screening of Key Components in Network Pharmacology Based on the Detectability of Components","authors":"Kaiye Peng,&nbsp;Sang Xu,&nbsp;Minpeng Li,&nbsp;Wei Li,&nbsp;Yun Zou,&nbsp;Mingxin Guo,&nbsp;Xia Wu","doi":"10.1002/rcm.10028","DOIUrl":"https://doi.org/10.1002/rcm.10028","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>The ingredients of traditional Chinese medicine (TCM) are complex and diverse and are often identified using the TCM systems pharmacology (TCMSP) database. However, the ingredients in this database exhibit significant homogeneity, which limits the comprehensive understanding of TCM's ingredient diversity and biological activity. Consequently, liquid chromatography–mass spectrometry (LC–MS) has become a key tool for the precise identification of TCM components.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In this study, the LC–MS was used to identify the components of a TCM herb. The identified components were then compared with the component data in the TCMSP database. A network pharmacological prediction of the components was subsequently performed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>An analysis of the four herb formula prescriptions (Ganmai Dazao decoction, Bazhen granule, Shaoyao Gancao decoction, and Zixue san) was conducted, revealing significant discrepancies between the LC–MS identification results and the components in the TCMSP database. The database components were found to be highly homogeneous.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This study underscores the pivotal function of LC–MS in the analysis of components of TCM, particularly in addressing issues of database homogeneity. The employment of LC–MS technology enhances the precision of ingredient identification and streamlines the identification of potential pharmacodynamic ingredients, thereby propelling TCM toward a more contemporary standing.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Larvicidal Diterpene Resin Acids in Melipona quadrifasciata Geopropolis via LC-ESI-MS/MS, GC–MS and Computational Analysis","authors":"Luís Guilherme Pereira Feitosa,&nbsp;Juliana Massimino Feres,&nbsp;Camila Capel Godinho,&nbsp;Lorena Carneiro Albernaz,&nbsp;Laila Salmen Espindola,&nbsp;Ricardo Vessecchi,&nbsp;Thais Guaratini,&nbsp;Norberto Peporine Lopes","doi":"10.1002/rcm.10025","DOIUrl":"10.1002/rcm.10025","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Dengue, an arboviral disease transmitted by the <i>Aedes aegypti</i> mosquito, is a major global public health problem challenge. Insecticides based on natural products can provide a good alternative to synthetic agents, as they are safer for both the environment and human health. This study evaluated the activity of geopropolis from stingless bees and <i>Apis mellifera</i> bees on <i>Ae. aegypti</i>, using mass spectrometry approaches to identify compounds with larvicidal potential against <i>Ae. aegypti</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The larvicidal activity of propolis from stingless bees and <i>A. mellifera</i>, as well as the <i>Melipona quadrisfasciata</i> geopropolis (a mixture of soil/clay and propolis), was evaluated against <i>Ae. aegypti</i> larvae (Rockefeller strain). ESI-MS/MS analyses were performed using a quadrupole/time-of-flight mass spectrometer for all geopropolis samples, the geopropolis from <i>Melipona quadrifasciata</i> was also analyzed using an ion trap instrument. The ESI-qTOF-MS/MS data were processed in a spectral similarity network using GNPS. Molecular annotation of potential compounds was performed using the <i>in silico</i> tool called NAP. Gas-phase fragmentation mechanisms were proposed in conjunction with computational chemistry studies. Silylated geopropolis samples were also analyzed by GC–MS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Geopropolis from the stingless bee <i>M. quadrifasciata</i> caused 90% and 100% mortality in <i>Ae. aegypti</i> larvae after 24 and 48 h of exposure, respectively, exhibiting the highest activity. Mass spectrometry-based molecular network approach supported the suggestion of discriminant compounds between active and inactive samples. The combination of NAP predictions with gas-phase reactions from ESI-MS/MS and EI-MS data facilitated the annotation of larvicidal compounds, including diterpene resin acids, such as dehydroabietic acid and its derivatives, abietic acid, and pimaranes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The combination of HPLC-MS/MS and GC–MS data suggests that diterpene resin acids contribute to the larvicidal effect of <i>M. quadrifasciata</i> geopropolis on <i>Ae. aegypti</i>, enhancing our understanding of potentially bioactive natural products against the arbovirus vector.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface Ionization of Carbaryl, Papaverine, Cocaine, Morphine, and Triethylamine by Heated Surface-Oxidized Metal Filaments of W, Re, Pd, Mo, Ti, and SUS304 Under Atmospheric Pressure: Ionization Mechanism","authors":"Kenzo Hiraoka,&nbsp;Dilshadbek T. Usmanov,&nbsp;Sherzod M. Akhmedov,&nbsp;Stephanie Rankin-Turner,&nbsp;Satoshi Ninomiya","doi":"10.1002/rcm.10029","DOIUrl":"10.1002/rcm.10029","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The objective of the present study is to investigate the ionization mechanisms for atmospheric pressure surface ionization (APSI).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>APSI of carbaryl, papaverine, cocaine, morphine, and triethylamine using heated surface-oxidized metal filaments of W, Re, Pd, Mo, Ti, and SUS304 were measured by mass spectrometry. Low-volatility analytes dissolved in methanol were desorbed by Leidenfrost phenomenon-assisted thermal desorption and introduced to the heated metal filament used as an emitter. Alkylamine benzene solutions were simply placed 10 mm below the filament.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Carbaryl, papaverine, cocaine, and morphine (M) gave protonated molecules [M+H]⁺ with little fragment ions. Triethylamine (TEA) gave both [TEA+H]⁺ and [TEA−H]⁺.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Because [M+H]⁺ was detected with little [M−H]⁺, which is usually detected as a major ion by vacuum surface ionization (VSI), it was concluded that [M+H]⁺ is formed by the proton transfer reaction between the protonated filament surface and the gas-phase analyte molecules approaching the solid surface. Namely, the heated metal filament acts as a Brønsted acid. This idea is supported by the APSI for TEA.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 12","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11927526/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of Free Amino Acid Concentrations in Bovine Plasma Using High-Pressure Liquid Chromatography With Electrospray Ionization Mass Spectrometry Detection","authors":"Laurie A. Reinhardt,&nbsp;Levi Svaren,&nbsp;Ritvik Marathe,&nbsp;Geoffrey I. Zanton,&nbsp;Michael L. Sullivan","doi":"10.1002/rcm.10027","DOIUrl":"https://doi.org/10.1002/rcm.10027","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Quantification of free amino acid concentrations in plasma has become an important tool in monitoring the health of dairy cows and health of their offspring under various management regimes, especially diet. Consequently, it was desirable to develop a robust, accurate, medium-throughput method to quantitate free amino acid concentrations in bovine plasma.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Bovine plasma was deproteinated with methanol and amino acids partially purified using cation exchange resin. Samples were then subjected to precolumn derivatization with phenyl isothiocyanate, followed by high-pressure liquid chromatography with positive electrospray ionization single quadrupole mass spectrometry detection for analysis. The corresponding ¹³C and ¹⁵N labeled amino acids (mass unit difference &gt; 3) were used as internal standards, while deuterium labeled standards were used for other metabolites.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>All 20 amino acids showed linear fits to their individual calibration curves (correlation coefficients &gt; 0.99) with concentration range of amino acids measured from 5 to 600 μM. Coefficient of variation (CV) values for the concentrations measured for all amino acids ranged from 2.0 to 6.7 for intraday aliquots and from 1.0 to 4.6 for interday aliquots with the exception of aspartic acid (11.1 and 12.6 for intraday and interday, respectively).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The use of a stable isotope labeled version of each amino acid analyte as internal standard added to plasma samples at the beginning of the procedure corrected for any losses, instrument variability, and chemistry of derivatization. Use of this method to quantify bovine plasma amino acids will allow better understanding of physiological processes underlying nutritional interventions in dairy production systems and may be more broadly applicable to ruminant and other animal production systems.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}