Rapid Communications in Mass Spectrometry最新文献

{"title":"Development of a Matrix-Assisted Laser Desorption Ionization High Resolution Mass Spectrometry Method for the Quantification of Camalexin and Scopoletin in Arabidopsis thaliana","authors":"Leonardo Parasecolo,&nbsp;Ivan M. Monsalvo,&nbsp;Nikola Kovinich,&nbsp;Demian R. Ifa","doi":"10.1002/rcm.9973","DOIUrl":"10.1002/rcm.9973","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Understanding plant defense mechanisms against pathogens is essential for enhancing agricultural productivity and crop protection. This study focuses on the quantification of camalexin and scopoletin, two critical phytoalexins in <i>Arabidopsis thaliana</i>, using mass spectrometry techniques. Precise measurement of these compounds provides insights into plant resistance and supports agricultural research.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Camalexin and scopoletin were quantified using matrix-assisted laser desorption ionization high-resolution mass spectrometry (MALDI-HRMS). The matrix and solvent conditions were optimized to maximize sensitivity and accuracy. MS/MS experiments confirmed compound identification with high mass accuracy (mass error &lt; 5 ppm). The method was validated through comparative analysis of wild-type (WT) and mutant <i>Arabidopsis</i> lines, using internal standards and multiple replicates to ensure precision and reliability.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The method exhibited high linearity for scopoletin (<i>R</i>² = 0.9992) and camalexin (<i>R</i>² = 0.9987) across concentration ranges of 0.16–5 and 0.31–5 μM, respectively. Limits of detection (LOD) were 0.16 μM for camalexin and 0.04 μM for scopoletin, with limits of quantification (LOQ) at 0.2 μM and 0.08 μM, respectively. Samples analysis demonstrated reliable quantification in WT and mutant lines, with significant reductions in camalexin and scopoletin levels observed in the <i>atwrky33-2</i> and <i>atmyb15-1</i> mutants, respectively. Additionally, the method detected sub-physiological concentrations, confirming its sensitivity and robustness for low-level detection.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study presents a validated, precise, and accurate MALDI-HRMS method for the quantification of camalexin and scopoletin in <i>Arabidopsis thaliana</i>. The approach not only enhances understanding of plant defense mechanisms but also offers potential applications for biotechnological and agricultural research, especially for investigating genetic variations and stress-induced phytoalexin production.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9973","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851689","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":"Establishment of a Mass Spectrometric Fingerprint of the Most Common Phytocannabinoids in Electrospray Ionization in Positive Ion Mode","authors":"Radwa Mahmoud,&nbsp;Amir Khajavinia,&nbsp;Sedigheh Barzegar,&nbsp;Randy W. Purves,&nbsp;Robert B. Laprairie,&nbsp;Anas El-Aneed","doi":"10.1002/rcm.9952","DOIUrl":"10.1002/rcm.9952","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Analysis of the phytocannabinoids holds significant importance because of their various pharmacological properties and potential therapeutic applications. Tandem mass spectrometry (MS/MS) coupled with electrospray ionization in positive ion mode is employed in this study to describe the collision-induced dissociation (CID) behavior of a series of common phytocannabinoids with the aim of establishing a generalized MS/MS fingerprint.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>Eight phytocannabinoids, namely, ∆⁹-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), tetrahydrocannabivarin (THCV), 11-hydroxy-Δ⁹-tetrahydrocannabinol (11-OH-THC), 6-hydroxy-cannabidiol (6-OH-CBD), and 7-hydroxy-cannabidiol (7-OH-CBD), were studied. A Quadrupole-Orbitrap mass spectrometer equipped with a heated electrospray ionization (HESI-Q Orbitrap) is used to provide accurate mass measurement data for single-stage and MS/MS analysis. In addition, a triple quadrupole-linear ion trap mass spectrometer was used to perform MS/MS and second-generation MS/MS (MS³) analyses.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>An abundant, singly charged [M + H]⁺ species during single-stage MS analysis was observed for all phytocannabinoids, with mass accuracies less than 5 ppm. Because of their structural similarities, all compounds showed some common fragmentation behavior in their MS/MS analysis. By comparing the fragmentation patterns and identifying diagnostic ions, a universal MS/MS fragmentation pattern was established. The structures of the various product ions proposed in the fragmentation pathway were confirmed with exact mass measurements and MS³ experiments.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The evaluated compounds contain varying functional groups, resulting in unique product ions, specific to each structure. The MS/MS fingerprints will be utilized in the future for the identification of new structures as well as the development of targeted quantification methods.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823475","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":"Colicin Immunity Proteins of Pathogenic Bacteria Detected by Antibiotic-Induced SOS Response, Plasmid Sequencing, MALDI-TOF-TOF Mass Spectrometry, and Top-Down Proteomic Analysis","authors":"Clifton K.  Fagerquist,&nbsp;Yanlin  Shi,&nbsp;Jihyun  Park","doi":"10.1002/rcm.9964","DOIUrl":"10.1002/rcm.9964","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale:</h3>\u0000 \u0000 <p>Plasmids can play a major role in the survival of pathogenic bacteria. Plasmids are acquired through horizontal gene transfer resulting in their spread across various strains, species and genera of bacteria. Colicins are bacterial protein toxins expressed by plasmid genes and released against co-located bacterial competitors.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods:</h3>\u0000 \u0000 <p>Three Shiga toxin-producing <i>E. coli</i> (STEC), whose genomes were sequenced previously, were analyzed using a combination of antibiotic induction, MALDI-TOF-TOF mass spectrometry, top-down proteomic analysis, and small plasmid sequencing. Protein biomarkers were identified using in-house software that matches protein mass and fragment ions of backbone cleavage by the <i>aspartic acid effect</i>. Predicted in silico protein structures assisted in the interpretation of protein ion fragmentation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results:</h3>\u0000 \u0000 <p>In addition to proteomic identification of phage-encoded Shiga toxin, we were able to identify plasmid-encoded immunity proteins for colicin D and E3. The genes for these plasmid-encoded proteins were not found in the previous genomic sequencing. However, resequencing of these strains for small plasmids revealed the genes to be present on 7–8 kb sized plasmids. Upstream of the colicin/immunity genes was an inverted repeat of the SOS/LexA box that represses gene expression until antibiotic challenge.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions:</h3>\u0000 \u0000 <p>Our top-down proteomic method demonstrates that it is possible to screen putative pathogenic bacteria (whose genomes have been sequenced in full, in part or not at all) for the presence of phage- and plasmid-encoded toxin and colicin genes under SOS control. Small plasmid sequencing confirmed the presence of colicin/immunity genes (and their regulatory control) suggested from induction and top-down proteomic analysis.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816786","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":"Integrative multi-omics reveals the mechanism of ulcerative colitis treated with Ma-Mu-Ran antidiarrheal capsules","authors":"Hailing Huang,&nbsp;Bailu Duan,&nbsp;Zhuang Huang,&nbsp;Shanshan Wang,&nbsp;Yuxin Wen,&nbsp;Qi Jiang,&nbsp;Pengyu Chen,&nbsp;Ping Huang,&nbsp;Jiajing Liu,&nbsp;Sili Zheng,&nbsp;Yan Ye,&nbsp;Dongning Zhang,&nbsp;Qiong Wang,&nbsp;Fang Huang,&nbsp;Jingjing Li,&nbsp;Lintao Han","doi":"10.1002/rcm.9939","DOIUrl":"10.1002/rcm.9939","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Ulcerative colitis (UC) is a chronic inflammatory gastrointestinal disease typically coexisting with intestinal microbiota dysbiosis, oxidative stress, and an inflammatory response. Although its underlying mechanism of action is unclear, Ma-Mu-Ran Antidiarrheal Capsules (MMRAC) have demonstrated significant therapeutic efficacy for UC.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The mechanism of action of MMRAC in the treatment of UC model was investigated by combining metabolomics, transcriptomics, and intestinal microbiota detection techniques.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The high-dose group of MMRAC was determined as the best therapeutic dose by pathological changes and biochemical indexes. Transcriptome analysis revealed that 360 genes were differentially altered after MMRAC treatment. Metabolomic analysis using colon tissue yielded 14 colon tissue metabolites with significant differences. Intestinal flora analysis showed that 26 major microorganisms were identified at the genus level.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Based on a thorough multi-omics analysis of transcriptomics, metabolomics, and gut flora, it was determined that MMRAC regulated cysteine and methionine metabolism, arginine biosynthesis, and sphingolipid metabolism and their respective genes BHMT, PHGDH, iNOS, and SPHK1, which in turn served to inhibit UC-generated inflammatory responses and oxidative stress. Additionally, MMRAC regulated the abundance of Coprococcus, Helicobacter, Sutterella, Paraprevotella, and Roseburia in the intestinal tracts of UC mice, which was regulated toward normal levels, thereby restoring normal intestinal function.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142811419","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":"Discovery and Characterization of Unusual O-Linked Glycosylation of IgG4 Antibody Using LC-MS","authors":"Dariusz J. Janecki,&nbsp;Chi-Ya Kao-Scharf,&nbsp;Andreas Hoffmann","doi":"10.1002/rcm.9969","DOIUrl":"10.1002/rcm.9969","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Consensus is that immunoglobulin IgG4 contains only N-linked glycosylation. The analysis of several batches of commercial biopharmaceutical product Dupixent using top-down intact mass spectrometry revealed that this IgG4 features a small amount of O-linked glycosylation in the Fab region. This is the first report of an O-linked glycosylation in an IgG4 antibody.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Monoclonal antibody solutions were subjected to cation exchange (CEX) and reverse phase (RP) chromatography and/or additional preconcentration/fractionation methods to prepare samples for subsequent analysis. Advanced MS analysis and fragmentation techniques (HCD, ETD, and EThcD) were employed to localize the O-linked glycosylation as well as elucidate the structure of the glycan(s).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>O-linked glycosylation in the IgG4 dupilumab was discovered by intact-MS. The probable location was narrowed down to four sites in the CH1 domain, and the structure of the O-linked glycan was determined to be of Core 1 type. The relative quantities of the modifications were low, but the glycosylation was consistently detected in several batches of Dupixent.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We discovered a rare glycosylation modification on dupilumab, an IgG4 antibody. The O-linked glycosylation was characterized and localized in the Fab region.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11635057/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142811415","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":"Adaptive Multicore Dual-Path Fusion Multimodel Extraction of Heterogeneous Features for FAIMS Spectral Analysis","authors":"Ruilong Zhang,&nbsp;Xiaoxia Du,&nbsp;Wenxiang Xiao,&nbsp;Hua Li","doi":"10.1002/rcm.9967","DOIUrl":"10.1002/rcm.9967","url":null,"abstract":"<div>\u0000 \u0000 <p>With the increasing application scenarios and detection needs of high-field asymmetric waveform ion mobility spectrometry (FAIMS) analysis, deep learning–assisted spectral analysis has become an important method to improve the analytical effect and work efficiency. However, a single model has limitations in generalizing to different types of tasks, and a model trained from one batch of spectral data is difficult to achieve good results on another task with large differences. To address this problem, this study proposes an adaptive multicore dual-path fusion multimodel extraction of heterogeneous features for FAIMS spectral analysis model in conjunction with FAIMS small-sample data analysis scenarios. Multinetwork complementarity is achieved through multimodel feature extraction, adaptive feature fusion module adjusts feature size and dimension fusion to heterogeneous features, and multicore dual-path fusion can capture and integrate information at all scales and levels. The model's performance improves dramatically when performing complex mixture multiclassification tasks: accuracy, precision, recall, f1-score, and micro-AUC reach 98.11%, 98.66%, 98.33%, 98.30%, and 98.98%. The metrics for the generalization test using the untrained xylene isomer data were 96.42%, 96.66%, 96.96%, 96.65%, and 97.60%. The model not only exhibits excellent analytical results on preexisting data but also demonstrates good generalization ability on untrained data.</p>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805725","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":"Remembering Robert Kinnear Boyd (1938-2024).","authors":"Pierre Thibault, Dietrich Volmer, David Goodlett, John Monaghan","doi":"10.1002/rcm.9963","DOIUrl":"https://doi.org/10.1002/rcm.9963","url":null,"abstract":"","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":" ","pages":"e9963"},"PeriodicalIF":1.8,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805724","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":"Forced Degradation Study of an Anti-Diabetic Drug Imeglimin: Impurity Profiling and Structure Elucidation Using LC-Q-ToF-MS/MS and NMR","authors":"Shiva Kumar Gogikar,&nbsp;Sibu Sen,&nbsp;Shivashankar Pathinti,&nbsp;Gananadhamu Samanthula,&nbsp;Amol G. Dikundwar","doi":"10.1002/rcm.9960","DOIUrl":"10.1002/rcm.9960","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The present study aims to establish structures of the degradation products of an anti-diabetic drug, Imeglimin (IMG) approved for the treatment of type 2 diabetes mellitus in the year 2021. Degradation pathways are proposed along with in silico toxicity assessments of the observed degradation products (DPs) of the drug.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A reversed-phase high-performance liquid chromatography (RP-HPLC), equipped with a photodiode array detector, was used to separate the observed DPs with a Phenomenex Luna PFP (250 × 4.6 mm, 5 μm) column, using 10 mM ammonium formate (pH 4.5) and methanol as mobile phase. Liquid chromatography quadrupole time of flight mass spectrometry (LC-Q-ToF-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy were employed for structural elucidation. Zeneth and Derek suites were used for in silico assessments.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of four degradation products were observed, which were successfully separated on an RP-HPLC. The structural characterization of three of the four DPs was achieved using LC-Q-TOF-MS/MS by employing electro spray ionization as well as atmospheric pressure chemical ionization. Additionally, DP-3 was isolated using a preparative HPLC and was characterized by NMR. Computationally predicted structures were compared with the experimental observations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>An HPLC method, capable of separating the Imeglimin and its four DPs, was developed and validated as per the ICH Q2(R1) guideline. Structure elucidation reveals a variety of products with metformin as one of the identified DPs along with a metabolite. The toxicity potential of DPs was assessed through docking studies.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805726","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":"A simple and cost-effective sample preparation and storage method for stable isotope analysis of atmospheric CO2 for GasBench II/continuous flow isotope ratio mass spectrometry","authors":"Savio Manaj,&nbsp;Sang-Tae Kim","doi":"10.1002/rcm.9941","DOIUrl":"10.1002/rcm.9941","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The stable isotope compositions of atmospheric CO₂ can provide useful insight into various geochemical processes and carbon cycles on Earth, which is critical for understanding of Earth's changing climate. Here, we present a simple and cost-effective analytical method for the collection and measurement of carbon and oxygen isotope compositions of atmospheric CO₂.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Air samples of ~150 mL were collected individually or collectively using our simple active air collection system and then extracted on a vacuum purification line to remove noncondensable gases and atmospheric water vapor. The efficiency of removing atmospheric water vapor was tested by using a magnesium perchlorate desiccant trap and a dry ice/ethanol trap. Lastly, a “J-Cut tube sealing/cracking method” was developed to store and transfer purified atmospheric CO₂ to the GasBench II and CF-IRMS system for δ¹³C and δ¹⁸O measurements.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The collective active air collection method combined with the full sample air extraction method for a 3-min transfer time or “Full 3m TE” yields the best analytical precision of 0.07‰ (δ¹³C) and 0.04‰ (δ¹⁸O). Removing atmospheric water vapor from air samples is not necessary for δ¹³C, but essential for δ¹⁸O measurements. The J-Cut tube sealing/cracking method shows a near 100% effectiveness for the storage and transfer of atmospheric or any CO₂.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>A simple and cost-effect method was developed for the collection, purification, storage, and isotopic analysis of indoor/outdoor atmospheric CO₂ samples for general users. This method utilizes a popular headspace gas sample preparation system for CF-IRMS and an easy-to-build vacuum purification line without involving complex and high-cost devices for the preparation of atmospheric CO₂.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11625694/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142794076","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":"Testing the Ce Limit of Mass Bias Correction Using 145Nd/142Nd as Normalizing Ratio in Radiogenic Neodymium Isotope Analysis by MC-ICP-MS","authors":"Torben Struve,&nbsp;Martin Zander,&nbsp;Katharina Pahnke","doi":"10.1002/rcm.9951","DOIUrl":"10.1002/rcm.9951","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Neodymium isotopes are a powerful geochemical tool that has widely been used in terrestrial and extraterrestrial studies. Modern multicollector inductively coupled plasma mass spectrometers (MC-ICP-MS) allow fast, accurate, and precise analysis of the radiogenic Nd isotope ratio ¹⁴³Nd/¹⁴⁴Nd. These analyses comprise relatively high instrumental mass bias that is typically corrected for using the stable ¹⁴⁶Nd/¹⁴⁴Nd of 0.7219 and an exponential law. The instrument is usually tuned to optimize the operating conditions for isotope analysis, but this tuning is a trade-off primarily between signal intensity, stability, and accuracy. Alternative, more effective approaches for mass bias correction have been proposed that use ¹⁴⁵Nd/¹⁴²Nd as normalizing ratio. However, one drawback of using this ratio is that the efficient removal of Ce from Nd is required to minimize the effect of isobaric interference of ¹⁴²Ce on ¹⁴²Nd.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Here, we analyzed international Nd and rock reference materials using a Thermo Scientific Neptune <i>Plus</i> MC-ICP-MS to evaluate the sensitivity of ¹⁴⁵Nd/¹⁴²Nd-based mass bias correction to varying Ce/Nd and in comparison with the commonly used ¹⁴⁶Nd/¹⁴⁴Nd-based correction.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our results show that the corrected ¹⁴³Nd/¹⁴⁴Nd of Ce-doped JNdi-1 and Ce-containing USGS BCR-2, NOD-A-1, and NOD-P-1 reference materials are insensitive to Ce/Nd of up to ~1.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The correction of instrumental mass bias with ¹⁴⁵Nd/¹⁴²Nd as a normalizing ratio yields, as previously suggested, improved trueness and precision of ¹⁴³Nd/¹⁴⁴Nd data in comparison with ¹⁴⁶Nd/¹⁴⁴Nd-based corrections, even under high Ce/Nd of ~1. This allows improved optimization of signal intensity during instrument tuning, which is particularly useful for natural samples with low Nd content. [Correction added on 10 December 2024, after first online publication: The Results and Conclusions in Abstract has been corrected in this version.]</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11623368/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142783592","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}