Journal of Mass Spectrometry最新文献

{"title":"Detection and Behaviors of TEMPO Derivatives in Seven Mass Spectrometry Ionization Methods","authors":"Kin-ichi Oyama,&nbsp;Seanghai Hor,&nbsp;Masaki Tsukamoto,&nbsp;Hedong Zhang","doi":"10.1002/jms.5122","DOIUrl":"10.1002/jms.5122","url":null,"abstract":"<p>Four 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) derivatives with molecular weights of 339–1131 Da were synthesized to investigate their ionization behaviors in fast atom bombardment (FAB), electron ionization (EI), direct analysis in real time (DART), electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), atmospheric pressure photoionization (APPI), and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). These include 4-dodecanoylamino-2,2,6,6-tetramethyl-1-piperidinyloxy (<b>1</b>), 4-dodecylamino-2,2,6,6-tetramethyl-1-piperidinyloxy (<b>2</b>), <i>N</i>,<i>N</i>′-bis(2,2,6,6-tetramethyl-1-oxyl-4-piperidinyl)dodecanediamide (<b>3</b>), and bis-cholesterol TEMPO derivative <b>4</b>. For TEMPO derivatives <b>1</b> and <b>2</b> (molecular weights: 353 Da and 339 Da), [M]⁺, [M+H]^+•, and [M+2H]⁺ peaks were detected. TEMPO derivative <b>3</b>, containing two TEMPO moieties, showed [M]^+•, [M+H]⁺, [M+2H]^+•, and [M+3H]⁺ peaks. EI was optimal for smaller derivatives, as molecular ion peaks were predominant. For larger analytes, molecular ion intensities weakened, favoring hydrogen adduct peaks. EI and DART-MS failed to detect bis-cholesterol TEMPO derivative <b>4</b>. Under APCI and APPI-MS, N–O bond cleavage was observed. MALDI-MS detected only hydrogen adduct peaks. FAB, ESI, APCI, and APPI-MS detections varied with scan numbers, unlike EI, DART, and MALDI-MS.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11924985/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143663518","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":"Development of an LC–MS/MS Method for Quantifying Occidiofungin in Rabbit Plasma","authors":"Andrew Cothrell,&nbsp;Ravi S. Orugunty,&nbsp;Leif Smith","doi":"10.1002/jms.5121","DOIUrl":"10.1002/jms.5121","url":null,"abstract":"<p>Fungal infections are caused by opportunistic pathogens that can be life threatening and have been growing in prevalence. Many clinically relevant pathogens have resistance to or are developing resistance to the commonly used antifungal treatments. Occidiofungin (OCF) is a unique cyclic lipoglycopeptide with a novel structure that includes noncanonical amino acid in its covalent structure. It exhibits broad spectrum antifungal activity and has activity against drug resistant <i>Candida</i> species. Occidiofungin is a fungicidal compound that has a novel mechanism of action in which it disrupts higher order actin structures. Currently, occidiofungin is being developed for use in treating vulvovaginal candidiasis (VVC) and recurrent vulvovaginal candidiasis (RVVC). This study describes the development and application of a bioanalytical method for the quantification of occidiofungin in rabbit plasma. Method development was performed to quantify occidiofungin in rabbit plasma after intravaginal administration of a hydrogel containing occidiofungin. The method was validated with a linear range of 30–15 000 ng/mL in rabbit plasma. Precision, accuracy, calibration curve linearity, and stability of drug in plasma were established in quality controls. Extract stability, matrix effects, and recovery of drug in the extract were also determined. This study supported a repeat dose toxicity study in rabbits to determine occidiofungin pharmacokinetics and toxicokinetics. The pharmacokinetic and toxicokinetic primarily showed plasma concentrations of occidiofungin below the limit of quantification (BLOQ), suggesting that OCF-B does not readily cross the vaginal epithelial membrane.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11925553/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143670005","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":"In Vitro and In Vivo Assessment of Antidiabetic Activity of Cupressus torulosa D. Don Needles, Their LCQTOFMS Assisted Metabolite Profiling, and Implications for Diabetes Management","authors":"Radhika Khanna,&nbsp;H. R. Chitme,&nbsp;Khushaboo Bhadoriya,&nbsp;Y. C. Tripathi,&nbsp;V. K. Varshney","doi":"10.1002/jms.5117","DOIUrl":"https://doi.org/10.1002/jms.5117","url":null,"abstract":"<div>\u0000 \u0000 <p>Diabetes mellitus (DM) is a prevalent metabolic disorder attributed to insulin secretion and action defects, affecting a growing adult population with hyperglycemia expected to reach 578 million by 2030. This study explores the antidiabetic potential of 25% aqueous methanol extract of <i>Cupressus torulosa</i> needles, utilizing in vitro and in vivo assays. In the <i>α</i>-glucosidase inhibition assay, the extract exhibited significant in vitro antidiabetic activity with an IC₅₀, 123.45 ± 1.8 μg/mL, comparable to the standard drug acarbose (IC₅₀, 58.21 ± 3.1 μg/mL). Toxicity assessment indicated non-toxic nature of the extract at 2000 mg/kg b.w. In STZ-induced diabetic mice, it displayed dose-dependent antihyperglycemic effects, evident at the fourth hour and 14th day, paralleling the positive control glibenclamide. In the chemical profiling of the extract using UPLC-QTOF-MS, the mobile phases consisted of 0.1% formic acid in water (Solvent A) and 100% methanol (Solvent B). The gradient elution started with 5% B (0 to 2 min) and gradually increased to 95% B by 25 min, followed by a post-run time of 2 min. Preliminarily, 50 constituents were identified, predominantly phenolics, with hypoglycemic effects attributed to flavonoids like (−)-epicatechin, amentoflavone, and cupressuflavone, as well as iridoid <i>O</i>-glycoside, exemplified by haprpagoside. Further studies are needed to assess the long-term efficacy, safety, and molecular mechanisms of the extract of <i>C. torulosa</i> needles in diabetes management.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481401","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":"Mass Spectrometry–Based Proteomics in Clinical Diagnosis of Amyloidosis and Multiple Myeloma: A Review (2012–2024)","authors":"Katerina Kratka,&nbsp;Pavel Sistik,&nbsp;Ivana Olivkova,&nbsp;Pavlina Kusnierova,&nbsp;Zdenek Svagera,&nbsp;David Stejskal","doi":"10.1002/jms.5116","DOIUrl":"https://doi.org/10.1002/jms.5116","url":null,"abstract":"<p>Proteomics is nowadays increasingly becoming part of the routine clinical practice of diagnostic laboratories, especially due to the advent of advanced mass spectrometry techniques. This review focuses on the application of proteomic analysis in the identification of pathological conditions in a hospital setting, with a particular focus on the analysis of protein biomarkers. In particular, the main purpose of the review is to highlight the challenges associated with the identification of specific disease-causing proteins, given their complex nature and the variety of posttranslational modifications (PTMs) they can undergo. PTMs, such as phosphorylation and glycosylation, play critical roles in protein function but can also lead to diseases if dysregulated. Proteomics plays an important role especially in various medical fields ranging from cardiology, internal medicine to hemato-oncology emphasizing the interdisciplinary nature of this field. Traditional methods such as electrophoretic or immunochemical methods have been mainstay in protein detection; however, these techniques are limited in terms of specificity and sensitivity. Examples include the diagnosis of multiple myeloma and the detection of its specific protein or amyloidosis, which relies heavily on these conventional methods, which sometimes lead to false positives or inadequate disease monitoring. Mass spectrometry in this respect emerges as a superior alternative, providing high sensitivity and specificity in the detection and quantification of specific protein sequences. This technique is particularly beneficial for monitoring minimal residual disease (MRD) in the diagnosis of multiple myeloma where traditional methods fall short. Furthermore mass spectrometry can provide precise typing of amyloid proteins, which is crucial for the appropriate treatment of amyloidosis. This review summarizes the opportunities for proteomic determination using mass spectrometry between 2012 and 2024, highlighting the transformative potential of mass spectrometry in clinical proteomics and encouraging its wider use in diagnostic laboratories.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5116","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439066","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":"CID-Induced Formation of Deprotonated Cyclic Peptide Ions From Anionic Adducts","authors":"Maciej Modzel,&nbsp;Piotr Stefanowicz","doi":"10.1002/jms.5114","DOIUrl":"https://doi.org/10.1002/jms.5114","url":null,"abstract":"<div>\u0000 \u0000 <p>MS analysis of cyclic peptides in negative ion mode has been a challenge, in particular if the peptide does not contain acidic functional groups. In this paper, we present a way to easily produce negative ions from anionic peptide adducts, utilising collision-induced dissociation (CID)-mediated elimination. Using two different mass spectrometers, we have generated series of adducts of three cyclic and one linear peptide with various anions. They were then isolated and subjected to CID with a range of collision energies. The deprotonation percentage was then calculated from the resultant spectrum, and compared between the spectrometers, as well as with an external reference—proton affinity values. The susceptibility to deprotonate by detaching a HX moiety is proportional to the proton affinity of the X⁻ species. Also, the linear peptide deprotonated more readily than the cyclic ones. On the other hand, lack of amino or acidic groups resulted in higher collision voltage (CV) necessary for the formation of deprotonated species. Moreover, the exact propensity for neutral loss depends on the ion temperature, which differs between mass spectrometers. We have developed a facile method for generating peptide anions for MS analysis of cyclic peptides, which works even if the peptide in question does not have easily ionisable groups. The deprotonated species generated in this way can be fragmented again in order to identify the peptide.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439090","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":"Comparison of Mid-Infrared and Ultraviolet Lasers Coupled to the MALDESI Source for the Detection of Secondary Metabolites and Structural Lipids in Arabidopsis thaliana","authors":"Sarah M. Ashbacher,&nbsp;Jeffrey G. Manni,&nbsp;David C. Muddiman","doi":"10.1002/jms.5118","DOIUrl":"https://doi.org/10.1002/jms.5118","url":null,"abstract":"<p>Matrix-assisted laser desorption electrospray ionization (MALDESI) conventionally utilizes a mid-infrared (IR) laser for the desorption of neutrals, allowing for detection of hundreds to thousands of analytes simultaneously. This platform enables mass spectrometry imaging (MSI) capabilities to not only detect specific molecules but also reveal the distribution and localization of a wide range of biomolecules across an organism. However, an IR laser comes with its disadvantages when imaging plants. At a mid-IR wavelength (2970 nm), the compartmentalized endogenous water within the leaf structure acts as an internal matrix, causing rapid heating, and, in turn, degrades the spatial resolution and signal quality. An ultraviolet (UV) laser operates at wavelengths that overlap with the absorption bands of secondary metabolites allowing them to serve as sacrificial matrix molecules. With the integration and optimization of a 355 nm UV laser into the MALDESI-MSI NextGen source for the analysis of plants, we were able to detect diverse molecular classes including flavonoids, fatty acid derivatives, galactolipids, and glucosinolates, at higher ion abundances when compared to the mid-IR laser. These results show that re-visiting UV-MALDESI-MSI, without the need for an exogenous matrix, provides a promising approach for the detection and imaging of important analytes in plants.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5118","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431584","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":"Minimizing Variable Downhole Fractionation in U–Pb Zircon Geochronology by LA-MC-ICP-MS at Smaller Spot Size","authors":"Saurabh Singhal,&nbsp;Sandeep Singh,&nbsp;Dharmendra Singh","doi":"10.1002/jms.5115","DOIUrl":"https://doi.org/10.1002/jms.5115","url":null,"abstract":"<div>\u0000 \u0000 <p>The development of LA-ICPMS and LA-MC-ICPMS resulted in analytical methods for zircon geochronology using a 20- to 60-μm laser spot size. A high amount of complexly zoned zircons promotes the requirement of U–Pb dating at smaller spot sizes. When spot size reduces, downhole fractionation (DHF) increases, increasing the DHF discrepancy between zircon grains and the primary reference zircon standard and resulting in inaccurate results. With MC-ICPMS's high sensitivity and multi-collector capabilities, this work attempts to accurately determine age with spatial resolutions below 20 μm. Three well-characterized zircon standards (91500, GJ-1, and Plešovice) were tested at spot sizes of 35, 20, 15, and 10 μm. Laser and mass spectrometry tuning, laser shot count, and ablation time have been optimized to reduce the DHF effect on measurement accuracy. Static ablation of 35- to 15-μm spots with 150 laser shot counts (30 s) yielded precision of less than 1.5% and age offset of less than 2%. The DHF differs significantly from the reference standard and two test zircon samples used for validation, with an age offset of 4% at 10-μm spot sizes. Masking shot counts from the end enhanced accuracy, notably for lower laser shot counts and shorter ablation times. At 75 laser shot counts, precision reached 1.4% and age offsets reduced to 1.6% for ²⁰⁶Pb/²³⁸U age. This method minimizes laser shot counts to avoid sampling two age groups. Higher zircon DHF variability at smaller spot sizes may influence a well-calibrated, sensitive LA-MC-ICP-MS analytical figure of merit.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439092","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":"Mechanistic Insights Into the Dissociative Photoionization Pathways of Ethyl Propionate: A Combined Experimental and Theoretical Approach","authors":"Huanhuan Wang,&nbsp;Xiaobin Shan,&nbsp;Fuyi Liu,&nbsp;Zhenya Wang,&nbsp;Liusi Sheng,&nbsp;Ran Sui","doi":"10.1002/jms.5119","DOIUrl":"https://doi.org/10.1002/jms.5119","url":null,"abstract":"<div>\u0000 \u0000 <p>Ethyl propionate (C₅H₁₀O₂, EP) has been extensively studied in the fields of biofuels and atmospheric chemistry. However, its vacuum ultraviolet (VUV) photoionization has not been investigated. This study examines the photoionization process of EP using tunable VUV synchrotron radiation, coupled with a reflectron time-of-flight mass spectrometer. This method yielded the photoionization mass spectrum of EP and photoionization efficiency (PIE) spectra of 10 identified fragment ions (i.e., C₄H₇O₂^+., C₃H₇O₂^+., C₃H₆O₂^+., C₃H₅O₂^+., C₃H₆O^+., C₃H₅O^+., C₃H₄O^+., C₂H₅O^+., C₂H₅^+., and C₂H₄^+.). The results, interpreted with the aid of high-accuracy theoretical calculations, conclude possible formation mechanisms for each fragment ion. In the dissociation pathway of EP's cation, intramolecular hydrogen shifts and bond cleavage are the predominant processes. The C₃H₇O₂^+. and C₂H₄^+. reaction channels do not arise from one-step bond cleavage, but their reaction energy barriers are influenced by product energy, making them comparable to direct reaction channels. The active reaction sites within the molecules are elucidated using Laplacian bond order (LBO). Rate constants are calculated using RRKM theory, which confirms the kinetic factors governing the EP reaction process. This study provides a detailed understanding of the photoionization and dissociation of the main ions of EP within the 9.35–15.50 eV photon energy range.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143423834","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":"Zn(II) Affinity and Structural Conformations of 2His-2Cys Zinc Finger-Like Motif Peptide Determined by Ion Mobility–Mass Spectrometry and PM6 Molecular Modeling","authors":"Richmond A. Adomako,&nbsp;Michael B. Owusu,&nbsp;Rebekah K. Oberdick,&nbsp;Kwabena Senyah,&nbsp;Perfect Asare,&nbsp;Riccardo Spezia,&nbsp;Laurence A. Angel","doi":"10.1002/jms.5113","DOIUrl":"10.1002/jms.5113","url":null,"abstract":"<div>\u0000 \u0000 <p>This study focuses on investigating the conformational structure and zinc(II) affinity of a zinc finger-like motif (ZFM) peptide with the sequence acetyl-<b>His</b>_<b>1</b><b>-Cys</b>_<b>2</b>-Gly₃-Pro₄-Gly₅-<b>His</b>_<b>6</b><b>-Cys</b>_<b>7</b>, where bold highlights the potential zinc(II) binding sites. Zinc fingers are crucial protein motifs known for their high specificity and affinity for zinc ions. The ZFM peptide's sequence contains the 2His-2Cys zinc-binding sites similar to those in natural zinc finger proteins but without the hydrophobic core, making it a valuable model for studying zinc(II)–peptide interactions. Previous research on related peptides showed that collision cross sections and B3LYP modeling predicted that the His-2Cys-carboxyl terminus coordination of zinc(II) was more stable than the 2His-2Cys. Employing a comprehensive approach integrating ion mobility–mass spectrometry and theoretical modeling techniques, various zinc(II) binding modes of the ZFM have been thoroughly compared to ascertain their influence on the competitive threshold collision-induced dissociation method for measuring the relative gas-phase Zn(II) affinity of the ZFM peptide. The measured Zn(II) affinity of ZFM is greater than those measured recently for two peptides with similar primary structures, acetyl-<b>His</b>_<b>1</b><b>-Cys</b>_<b>2</b>-Gly₃-Pro₄-Gly₅-Gly₆-<b>Cys</b>_<b>7</b> and acetyl-<b>Asp</b>_<b>1</b>-<b>His</b>_<b>2</b>-Gly₃-Pro₄-Gly₅-Gly₆-<b>Cys</b>_<b>7</b>, indicating the preference for the His₁-Cys₂-His₆-Cys₇ side groups for coordinating zinc(II) over the His-2Cys-carboxyl terminus or Asp-His-Cys-carboxyl terminus in these related heptapeptides.</p>\u0000 </div>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 3","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143414332","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":"Erratum—Integrating DFT and CI-MS Techniques to Assess Benzophenone Derivatives in Food Packaging: Implications for Enhancing Food Quality and Safety","authors":"Manjeet Bhatia","doi":"10.1002/jms.5105","DOIUrl":"10.1002/jms.5105","url":null,"abstract":"<p>The corrected enthalpy (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Δ</mi>\u0000 <mi>H</mi>\u0000 </mrow>\u0000 <annotation>$$ Delta mathrm{H} $$</annotation>\u0000 </semantics></math>) and free energy (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Δ</mi>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 <annotation>$$ Delta mathrm{G} $$</annotation>\u0000 </semantics></math>) values for reactions of benzophenone derivatives with various CI-MS reagent ions are presented in Table 1. The values for reactions with NO⁺ and O<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msubsup>\u0000 <mrow></mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <mrow>\u0000 <mo>+</mo>\u0000 </mrow>\u0000 </msubsup>\u0000 </mrow>\u0000 <annotation>$$ {}_2^{+} $$</annotation>\u0000 </semantics></math> have been adjusted, as they were previously overestimated in Table 2.</p>","PeriodicalId":16178,"journal":{"name":"Journal of Mass Spectrometry","volume":"60 2","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jms.5105","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143006514","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}