Rapid Communications in Mass Spectrometry最新文献

{"title":"Combining Laser-Induced Edition to Collision-Induced Sequencing of Digital Oligomers in a Single Gas-Phase Experiment.","authors":"Clothilde Comby-Zerbino, Jean-François Lutz, Luke MacAleese, Laurence Charles","doi":"10.1002/rcm.10016","DOIUrl":"https://doi.org/10.1002/rcm.10016","url":null,"abstract":"<p><strong>Rationale: </strong>To increase the confidentiality level of molecular tags, binary information can be hidden in sequence-defined oligomers using isobaric monomers including a photo-sensitive one, which mass can be modified upon light irradiation. Reading such secured data requires light edition prior to MS/MS sequencing, which was investigated here in a single gas-phase workflow.</p><p><strong>Methods: </strong>Oligo (phosphodiester)s made of units with either light-sensitive ortho- or light-inert para-nitrobenzyl side-group were electrosprayed as deprotonated oligomers and sampled in an ion trap instrument equipped with various light sources. Nanosecond-pulsed laser (266 or 365 nm) and CW laser (375 nm) irradiations were compared for their efficiency to induce photo-cleavage of all o-nitrobenzyl moieties in laser-induced dissociation and to produce sufficient amounts of edited oligomers to achieve full coverage of their sequence in collision-induced dissociation.</p><p><strong>Results: </strong>While cleavage of photo-sensitive moieties was never fully achieved with the pulsed laser, photo-cleavage of all o-nitrobenzyl side-groups readily occurred with the CW laser, as monitored by successive losses of o-nitrobenzaldehyde from the irradiated chains. Time required for maximal production of edited oligomers increased with their number of reactive units but shorter irradiation steps were found sufficient to produce enough secondary precursors to achieve full sequence coverage in MS/MS.</p><p><strong>Conclusions: </strong>Laser-induced modification of light-sensitive units allowed monotonic sequences of two isobaric monomers to be turned into MS/MS readable sequences. This gas-phase experiment enables a much higher throughput compared with the 1-h irradiation requested for the oligomer edition when performed in solution.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":" ","pages":"e10016"},"PeriodicalIF":1.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143565730","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":"Determination of K Isotope Compositions in Sedimentary Rocks and Their Implications for Discriminating Sediment Origin","authors":"Meng-Meng Cui,&nbsp;Frédéric Moynier,&nbsp;Ben-Xun Su,&nbsp;Yan Hu","doi":"10.1002/rcm.10015","DOIUrl":"https://doi.org/10.1002/rcm.10015","url":null,"abstract":"<div>\u0000 \u0000 <p>The advent of a new generation of collision-cell multicollector inductively-coupled-plasma mass-spectrometers (CC–MC–ICP–MS), the Nu sapphire, has provided a new venue in achieving higher precision K isotopic compositions compared to the older generation of instruments. Here, we take advantage of this new technology to report the K isotopic compositions of eight sediment reference materials. The K isotopic compositions (reported as the δ⁴¹K representing the ⁴¹K/³⁹K ratios) for these sediment reference materials span a range of 0.2‰: −0.42 ± 0.04‰ (BCSS-1), −0.51 ± 0.07‰ (MESS-1), and −0.43 ± 0.01‰ (MESS-4) for three marine sediments, −0.35 ± 0.07‰ (NIST-SRM 1646a) for estuarine sediment, −0.40 ± 0.06‰ (NIST-SRM 2704) and −0.40 ± 0.05‰ (SWR-3) for two river sediments, −0.55 ± 0.04‰ (NIST-SRM 1d) for limestone, and −0.46 ± 0.00‰ (SBC-1) for marine shale. The high-precision K isotopic data presented herein provide a valuable reference for future quality control and interlaboratory comparisons. Data compilation reveals that biogenic sediments show extremely low K concentrations (K₂O = 0.001–0.048 wt.%) and large K isotopic variations (δ⁴¹K = −1.88–0.94‰) with an average value of −0.001‰, whereas the abiogenic sediments are featured with light K isotopes (average δ⁴¹K value of −0.47‰) and high K concentrations (K₂O = 0.52 ~ 4.29 wt.%). This finding suggests that the variation of K isotopes may serve as a useful tool for discriminating the various geneses of sediments.</p>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489937","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 Electron Ionization Fragmentation Pathways for Regioisomeric Ethoxy and Methoxymethyl Substituted Benzoate Esters","authors":"C. Randall Clark,&nbsp;Younis Abiedalla","doi":"10.1002/rcm.10013","DOIUrl":"https://doi.org/10.1002/rcm.10013","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>This study compares the EI fragmentation mechanisms for the regioisomeric 2-, 3-, and 4-ethoxy and methoxymethyl substituted methyl benzoates. These compounds represent isomerism in disubstituted aromatic ring and position of oxygen in the ether substituent. These esters are required synthetic intermediates for the design and synthesis of phenethylamine analogs as potential new drug substances. Regioisomerism of substituents and heteroatoms position often plays a significant role in drug action, potency, and MS fragmentations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The ethoxy substituted isomers were obtained from commercial source. The methoxymethyl substituted isomers were prepared from 2-, 3-, and 4-(chloromethyl)benzoyl chloride by methoxide displacement using Na/methanol. The D₃-methyl esters were prepared by acid-catalyzed ester exchange using methanol-D₄ and ethyl esters as substrates. The compounds were evaluated using GC, stable isotope, EI, and MS/MS studies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The major EI-MS fragments for methyl ethoxybenzoates are <i>m/z</i> 152, 149, and a base peak (3- and 4-substituted isomers) at <i>m/z</i> 121 from the loss of ethene, methoxy radical, and carbomethoxy radical, respectively. The <i>ortho</i> effect in methyl 2-ethoxybenzoate yields a base peak at <i>m/z</i> 120 and other unique cations at <i>m/z</i> 133, 147, and 165 due to the interaction of <i>ortho-</i> side chains. The major <i>ortho</i> effect in methyl 2-methoxymethylbenzoate arises from the ease of formation of the hydrogen rearrangement product yielding the <i>m/z</i> 133 base peak and inhibiting the formation of <i>m/z</i> 121 and 179 ions observed in 3- and 4-substituted isomers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The methoxymethyl substituted isomers yield more fragments than the ethoxy isomers. Thus, the alkyl ether is a more active participant in the fragmentation processes than the aromatic/phenolic ether for the ethoxy series. The major <i>ortho</i> effect in this series favors the distonic molecular radical cation formation yielding the <i>m/z</i> 133 base peak for the 2-substituted isomer and inhibiting the formation of <i>m/z</i> 121 and 179 species.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489936","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":"The Identification and Quantification of the Positional Isomers of Dimethylbipyridine by Ion Mobility Mass Spectrometry Analysis of Their Gas Phase Complexes","authors":"Xiaopeng Peng,&nbsp;Jianglong Du,&nbsp;Long Chen,&nbsp;Keqi Ye,&nbsp;Jiacheng Ye,&nbsp;Yinghua Yan,&nbsp;Chuan-Fan Ding","doi":"10.1002/rcm.10003","DOIUrl":"https://doi.org/10.1002/rcm.10003","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Dimethylbipyridine (DMDP) serves as a versatile industrial intermediate, with methyl substitutions at distinct positions tailored for varied applications, including the synthesis of DNA reagents and proton receptors. However, the pronounced structural and chemical similarities among its isomers underscore the critical need for an effective method to achieve their quantification and precise identification.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This study developed a straightforward, swift, and effective approach for the identification and quantification of two dimethylbipyridine positional isomers, namely, 6,6′-dimethyl-2,2′-bipyridine and 4,4′-dimethyl-2,2′-bipyridine based on the analysis of ion mobility spectrometry (IMS) of their cyclodextrin complex ion in gas phase. Moreover, their spatial conformations and cross sections were simulated by theoretical calculations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The complex associated with γ-CD exhibited superior separation, achieving an Rp-p of 0.823. And the theoretical computational simulation results are in good alignment with the experimental results, with a computed error value of less than 12.02%. Additionally, the relative quantification of the two DMDP isomers in a mixed solution was examined, yielding very well linear correlation coefficients (<i>R</i>² &gt; 0.99).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This study presents a highly promising method for the identification and quantification of two positional isomers of dimethylbipyridine (DMDP). Compared to conventional analytical methods such as HPLC, this approach offers advantages of simplicity, speed, and the elimination of chemical derivatization. It provides a novel perspective for the identification of DMDP isomers in chemical research and industrial applications.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489754","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":"Carbon and Nitrogen Isotopic Composition of Duplicate Diet of the Japanese","authors":"Jun Yoshinaga","doi":"10.1002/rcm.10014","DOIUrl":"https://doi.org/10.1002/rcm.10014","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Carbon and nitrogen stable isotope ratios (δ¹³C and δ¹⁵N) of whole diet have rarely been measured to date though the isotope ratios in human sample have been extensively used for diet and nutritional researches. In order to fully validate the isotope dietary analysis, isotopic information of whole diet is required.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>δ¹³C and δ¹⁵N of 150 duplicate diet samples collected in Japan during 2016–2017 were measured. Sixty-five males and 85 females (mean age: 45 years) donated duplicate diet sample of which δ¹³C and δ¹⁵N were measured by element analyzer-isotope ratio mass spectrometry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Mean δ¹³C and δ¹⁵N of the 150 duplicate diets were −24.3 (1.1) ‰ and 3.58 (0.93) ‰, respectively, with no gender- and age-dependent variation. δ¹⁵N of diet containing seafood (median: 3.60‰, <i>n</i> = 111) was significantly more elevated than that not containing seafood (3.01‰, <i>n</i> = 39). δ¹⁵N of Japanese diet is decreasing from 1990s to the present, which is consistent with the national statistics showing decreasing trend of seafood consumption of the Japanese. Contradictory to these observation, dietary δ¹⁵N was not elevated in diet samples from the elderlies though the diet of elderlies contained seafood more frequently than those of younger study participants.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>There were some uncertainties as to whether seafood is a major determinant of dietary δ¹⁵N of the Japanese. To further characterize dietary components that determine δ values, isotope ratio analysis of diet of known quantitative dietary components is warranted.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446764","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":"Combination of Metabolite Analysis and Network Pharmacology to Explore the Potential Anticough Mechanism of Protopine—A Marker in Zhi-Ke-Bao Tablets","authors":"Qi-Feng Zou,&nbsp;De-Jian Chen,&nbsp;Cheng-Jun Liu,&nbsp;Zi-Hao Chen,&nbsp;Xia Yang,&nbsp;Rong-Huang Xu,&nbsp;Zhen-Hui Zhou,&nbsp;Jian-Xin Chen,&nbsp;Wei Shi,&nbsp;Feng-Xiang Zhang","doi":"10.1002/rcm.10012","DOIUrl":"https://doi.org/10.1002/rcm.10012","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Protopine, an active alkaloid in <i>Papaver somniferum</i> L., was abundant in a well-known anticough traditional Chinese medicine preparation—Zhi-Ke-Bao tablets. Till now, the metabolism feature and anticough mechanism of protopine have not been fully elucidated, restricting its further development.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The metabolites of protopine in rats were profiled by using ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry, and its anticough targets and mechanism were predicted by network pharmacology.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In rats, a total of 19 metabolites were identified following ingestion of protopine (21 mg/kg/day, i.g.), including 4 in plasma, 6 in urine, 5 in feces, 10 in liver, 2 in spleen, 4 in lung, 3 in kidney, 3 in heart, and 3 in brain. The main metabolic features were ring-opening, methylation, demethylation, glucuronidation, sulfation, and hydroxylation. Among them, methylation, sulfation, and hydroxylation of protopine in vivo were revealed for the first time. The network pharmacology results show that protopine and its metabolites regulate physiological activities by acting on STAT3, SRC, CASP3, MTOR, MMP9, ESR1, and other targets, involving PI3K-Akt signaling pathway, FoxO signaling pathway, and TNF signaling pathway, etc.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The metabolic features of protopine and its potential mechanisms for anticough effects were outlined, providing data for further anticough pharmacological validation of protopine.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438826","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":"Pioneering Mass Spectrometry: A Tribute to My Mentor Jean-François Muller and His Enduring Legacy.","authors":"Gilles Frache","doi":"10.1002/rcm.10008","DOIUrl":"https://doi.org/10.1002/rcm.10008","url":null,"abstract":"<p><p>Professor Jean-François Muller, a distinguished figure in the field of mass spectrometry, made significant contributions to the advancement of analytical chemistry and its applications. As the founding director of the Laboratory of Mass Spectrometry and Laser Chemistry at the University of Metz, Muller played a pivotal role in establishing Metz as a leading center for mass spectrometry research. His pioneering work, particularly in the development of matrix-assisted laser desorption/ionization (MALDI) instrumentation and Fourier transform ion cyclotron resonance mass Spectrometry (FTICR MS), has had a profound impact on various scientific disciplines. This article commemorates Professor Muller's illustrious career and highlights his collaborative efforts with industrial partners such as Total, which led to groundbreaking advancements in MS analysis. I will delve into the key findings of my thesis which focused on instrumental developments for MALDI analysis and imaging, as well as personal reminiscences and the impact of his inspiring mentorship.</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":" ","pages":"e10008"},"PeriodicalIF":1.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143447578","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":"Fast Pyrolysis of Cigarette and Cigar Leaves: Differential Analysis of Their Heavy Products by Ultrahigh-Resolution Mass Spectrometry","authors":"Zihan Zhu,&nbsp;Cunyong Zhang,&nbsp;Yaqi Shi,&nbsp;Peng Zou,&nbsp;Naihong Ding,&nbsp;Kun Zong,&nbsp;Liangyuan Jia,&nbsp;Dongfeng Guo","doi":"10.1002/rcm.10011","DOIUrl":"https://doi.org/10.1002/rcm.10011","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The cigars have characteristic flavors in smoke when compared with cigarettes, and cigars from various origins also have a difference in taste. However, little information can be found about the difference in chemical components of smokes between cigar and cigarette as well as between cigars, so it is interesting to compare their pyrolysis product distribution.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The cigarette and cigar leaves were pyrolyzed in a microfluidized-bed reactor, and the pyrolysis vapors were condensed and collected using cold traps. Mass spectrometric analysis of condensed liquids was performed utilizing electrospray ionization-orbitrap mass spectrometry in both positive and negative ion modes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The mass spectra of condensable pyrolysis products of three tobacco leaves were obtained by Orbitrap-MS in both positive and negative ESI modes. The DBE values (to carbon atom number) and the relative distribution (to nitrogen or oxygen atom number) of different products were carefully compared and discussed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The main difference in pyrolysis products between cigarette and cigar leaves relates to N₁–N₂ class compounds in high-mass range as well as highly unsaturated nitrogenated compounds, while the one between two cigar leaves is associated with C_xH_yO_zN_5–9 and C_30-50H_yO_zN_w compounds. Besides, the oxygenated products that fall into the H/C &gt; 2 and O/C &lt; 1 ranges are also characteristic for Dominican cigar.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438825","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":"Determination of Collisional Cross Section Using Microscale High-Field Asymmetric Waveform ion Mobility Spectroscopy–Mass Spectrometry (FAIMS-MS)","authors":"Kristina Krasnova,&nbsp;Colin S. Creaser,&nbsp;James C. Reynolds","doi":"10.1002/rcm.10010","DOIUrl":"https://doi.org/10.1002/rcm.10010","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Collisional cross sections (CCS) are an important characteristic of gas-phase ions that are measured using ion mobility-mass spectrometry (IMS). Typically, CCS measurements are performed with drift-tube IMS or travelling-wave IMS. However. in a high-field asymmetric waveform ion mobility (FAIMS) device, ion heating effects make CCS determination more challenging. This research explores whether CCS can be predicted with microscale FAIMS by using known CCS standards.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>An Owlstone ultraFAIMS microscale FAIMS spectrometer was coupled to an Orbitrap Exactive mass spectrometer. Two different CCS standard mixtures (tetraalkylammonium halides [TAAHs] and poly-DL-alanine oligomers) were used to evaluate the system's potential to determine CCS. Test peptide bradykinin acetate and substance P were used to evaluate CCS determination accuracy for singly and doubly charged peptide species using external calibration with a series of poly-DL-alanine peptides for +1, +2 charge states.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Calibrations with excellent correlation coefficients (<i>R</i>² = 0.99) for both TAAHs and poly-DL-alanine were obtained. Good accuracy of determination was achieved for bradykinin [M + 2H]²⁺ with a ± 0.5% difference between experimental and published CCS at a dispersion field (DF) strength of 250 Td; the model proved less accurate for bradykinin [M + H]⁺ (±1.4% at 240 Td). The accuracy of determination for the [M + H]⁺ and [M + 2H]²⁺ ions of substance P was within ± 5% and ± 3% at 250 Td, respectively, while at higher DF values, accuracy decreased to approximately 5%.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Distinct relationships were observed between CCS and transmission CF with both calibrants. Optimum accuracy was obtained at DF 240–260 Td. At lower DF, accuracy is reduced by insufficient resolution of analyte ions from solvent cluster adducts, while at higher DF values, poor transmission becomes a factor. Nevertheless, these data suggest microscale FAIMS can conduct CCS measurements with reasonable accuracy when the compound being measured has similar structural features to the CCS standards used.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 10","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.10010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431707","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":"Part B: SLICE-MSI—A Machine Learning Interface for System Suitability Testing of Mass Spectrometry Imaging Platforms","authors":"Russell R. Kibbe,&nbsp;Quinn Mills,&nbsp;Alexandria L. Sohn,&nbsp;David C. Muddiman","doi":"10.1002/rcm.9990","DOIUrl":"https://doi.org/10.1002/rcm.9990","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The field of mass spectrometry imaging is currently devoid of standardized protocols or commercially available products designed for system suitability testing of MSI platforms. Machine learning is an approach that can quickly and effectively identify complex patterns in data and use them to make informed classifications, but there is a technical barrier to implementing these algorithms. Here we package the machine learning algorithms into a user-friendly interface to make community-wide implementation of this protocol possible.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The software package is built entirely in the Python language using the PySimpleGUI library for the construction of the interface, Pandas and Numpy libraries for data formatting and manipulation, and the Scikit-Learn library for the implementation of machine learning algorithms. Training data is collected on an instrument under clean and compromised conditions that can then be used to evaluate model performance and to train models prior to interrogating unknown samples before, during, or after experiments.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Detailed instructions are provided for the effective use of the SLICE-MSI software package to use machine learning to evaluate instrument condition of MSI platforms. File formatting and generalizable steps are clearly described to make the implementation of this package easy for multiple labs and different MSI platform configurations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>In this protocol, we demonstrate SLICE-MSI, a machine learning graphical user interface for efficient and easy implementation of QC instrument classification of mass spectrometry imaging platforms.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"39 8","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.9990","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431444","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}