المؤلفون: Wannenmacher, Anna^1,2 (AUTHOR), Lu, Wenchao¹ (AUTHOR), Amarasinghe, Chandika¹ (AUTHOR), Cerasoli, Frank² (AUTHOR), Donadio, Davide² (AUTHOR) ddonadio@ucdavis.edu, Ahmed, Musahid¹ (AUTHOR) mahmed@lbl.gov

المصدر: Journal of Chemical Physics. 4/14/2024, Vol. 160 Issue 14, p1-16. 16p.

مصطلحات موضوعية: *GLYCOLS, *TIME-of-flight mass spectrometry, *WATER clusters, *PHOTOIONIZATION, *ETHYLENE glycol, *MOLECULAR beams, *DENSITY functional theory

مستخلص: In the interstellar medium, diols and other prebiotic molecules adsorb onto icy mantles surrounding dust grains. Water in the ice may affect the reactivity and photoionization of these diols. Ethylene glycol (EG), 1,2-propylene glycol, and 1,3-propylene glycol clusters with water clusters were used as a proxy to study these interactions. The diol–water clusters were generated in a continuous supersonic molecular beam, photoionized by synchrotron-based vacuum ultraviolet light from the Advanced Light Source, and subsequently detected by reflectron time-of-flight mass spectrometry. The appearance energies for the detected clusters were determined from the mass spectra, collected at increasing photon energy. Clusters of both diol fragments and unfragmented diols with water were detected. The lowest energy geometry optimized conformers for the observed EG–water clusters and EG fragment–water clusters have been visualized using density functional theory (DFT), providing insight into hydrogen bonding networks and how these affect fragmentation and appearance energy. As the number of water molecules clustered around EG fragments (m/z 31 and 32) increased, the appearance energy for the cluster decreased, indicating a stabilization by water. This trend was supported by DFT calculations. Fragment clusters from 1,2-propylene glycol exhibited a similar trend, but with a smaller energy decrease, and no trend was observed from 1,3-propylene glycol. We discuss and suggest that the reactivity and photoionization of diols in the presence of water depend on the size of the diol, the location of the hydroxyl group, and the number of waters clustered around the diol. [ABSTRACT FROM AUTHOR]

المؤلفون: Huang, Dasheng^1,2,3 (AUTHOR), Li, Qing^1,4 (AUTHOR), Han, Yan¹ (AUTHOR), Xia, Shi-Yong⁵ (AUTHOR), Zhou, Jiawei¹ (AUTHOR), Che, Hanxiong¹ (AUTHOR), Lu, Keding⁶ (AUTHOR), Yang, Fumo⁷ (AUTHOR), Long, Xin¹ (AUTHOR), Chen, Yang¹ (AUTHOR) chenyang@cigit.ac.cn

المصدر: Journal of Environmental Sciences (Elsevier). Jul2024, Vol. 141, p215-224. 10p.

مصطلحات موضوعية: VOLATILE organic compounds, TIME-of-flight mass spectrometry, OZONE, AUTUMN, ATMOSPHERIC models, SUMMER, WINTER

مصطلحات جغرافية: SICHUAN Sheng (China), CHONGQING (China)

مستخلص: The complex air pollution driven by both Ozone (O 3) and fine particulate matter (PM 2.5) significantly influences the air quality in the Sichuan Basin (SCB). Understanding the O 3 formation during autumn and winter is necessary to understand the atmospheric oxidative capacity. Therefore, continuous in-site field observations were carried out during the late summer, early autumn and winter of 2020 in a rural area of Chongqing. The total volatile organic compounds (VOCs) concentration reported by a Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) were 13.66 ± 9.75 ppb, 5.50 ± 2.64 ppb, and 9.41 ± 5.11 ppb in late summer, early autumn and winter, respectively. The anthropogenic VOCs (AVOCs) and biogenic VOCs (BVOCs) were 8.48 ± 7.92 ppb and 5.18 ± 2.99 ppb in late summer, 3.31 ± 1.89 ppb and 2.19 ± 0.93 ppb in autumn, and 6.22 ± 3.99 ppb and 3.20 ± 1.27 ppb in winter. A zero-dimensional atmospheric box model was employed to investigate the sensitivity of O 3 -precursors by relative incremental reactivity (RIR). The RIR values of AVOCs, BVOCs, carbon monoxide (CO), and nitrogen oxides (NO x) were 0.31, 0.71, 0.09, and -0.36 for late summer, 0.24, 0.59, 0.22, and -0.38 for early autumn, and 0.30, 0.64, 0.33 and -0.70 for winter, and the results showed that the O 3 formation of sampling area was in the VOC-limited region, and O 3 was most sensitive to BVOCs (with highest RIR values, > 0.6). This study can be helpful in understanding O 3 formation and interpreting the secondary formation of aerosols in the winter. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Environmental Sciences (Elsevier) is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Lu, Zheng¹ (AUTHOR), Sun, Xuechun¹ (AUTHOR), Debraha, Augustine Atta² (AUTHOR), Du, Zhenxia^1,3 (AUTHOR) duzx@mail.buct.edu.cn

المصدر: Packaging Technology & Science. Feb2024, Vol. 37 Issue 2, p135-146. 12p.

مصطلحات موضوعية: *CLUSTER analysis (Statistics), GAS chromatography/Mass spectrometry (GC-MS), TIME-of-flight mass spectrometry, CYTOTOXINS, PRINCIPAL components analysis

مستخلص: This study utilized ultra‐high‐performance liquid chromatography combined with quadrupole time‐of‐flight mass spectrometry and gas chromatography–mass spectrometry techniques to analyze multiple batches of non‐polyvinyl chloride (PVC) soft bags exposed to three extractants. Based on an established library of relative response factors for more than 30 different polymer additives, analytical evaluation thresholds for large volume injectables were determined, and 30 extractables were screened and (semi‐)quantitatively analyzed. To identify variations in extractables between batches, multivariate statistical methods such as principal component analysis, heat map analysis, and hierarchical cluster analysis were employed. Additionally, a comprehensive risk assessment of extractables and a biosafety assessment of leachables were conducted. The results of the study revealed that the concentrations of two extractables exceeded the established safety threshold. Moreover, one of these extractables was deemed to pose a mutagenic risk based on the consistent findings of two (Q)SAR software tools. Notably, certain extractables exhibited discrepancies in their content between batches, with particular emphasis on 1,3‐bis(3,5‐di‐tert‐butyl‐4‐hydroxybenzyl)‐1,3,5‐triazinane‐2,4,6‐trione. This discrepancy led to inconsistencies in risk levels across batches. However, the levels of leachables detected in the non‐PVC soft bags were found to be within the safety threshold, and cytotoxicity assessments consistently yielded negative results for leachables. Consequently, this study provides valuable data for conducting batch stability investigations concerning extractables in large volume parenteral drug delivery containers and other forms of pharmaceutical packaging. [ABSTRACT FROM AUTHOR]

: Copyright of Packaging Technology & Science is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Nishimura, Hiroshi¹ (AUTHOR) nishimura.hiroshi.j03@kyoto-u.jp, Watanabe, Takashi¹ (AUTHOR)

المصدر: Rapid Communications in Mass Spectrometry: RCM. 7/30/2024, Vol. 38 Issue 14, p1-7. 7p.

مصطلحات موضوعية: *TIME-of-flight mass spectrometry, *WOOD, *MATRIX-assisted laser desorption-ionization, *BIOMASS conversion, *MASS spectrometry, *CYCLOTRON resonance, *ENVIRONMENTAL research

مستخلص: Rationale: This study overcomes traditional biomass analysis limitations by introducing a pioneering matrix‐free laser desorption/ionization (LDI) approach in mass spectrometry imaging (MSI) for efficient lignin evaluation in wood. The innovative acetic acid–peracetic acid (APA) treatment significantly enhances lignin detection, enabling high‐throughput, on‐site analysis. Methods: Wood slices, softwood from a conifer tree (Japanese cypress) and hardwood from a broadleaf tree (Japanese beech), were analyzed using MSI with a Fourier transform ion cyclotron resonance mass spectrometer. The developed APA treatment demonstrated effectiveness for MSI analysis of biomass. Results: Our imaging technique successfully distinguishes between earlywood and latewood and enables the distinct visualization of lignin in these and other wood tissues, such as the radial parenchyma. This approach reveals significant contrasts in MSI. It has identified intense ions from β‐O‐4‐type lignin, specifically in the radial parenchyma of hardwood, highlighting the method's precision and utility in wood tissue analysis. Conclusions: The benefits of matrix‐free LDI include reduced peak overlap, consistent sample quality, preservation of natural sample properties, enhanced analytical accuracy, and reduced operational costs. This innovative approach is poised to become a standard method for rapid and precise biomass evaluation and has important applications in environmental research and sustainable resource management and is crucial for the effective management of diverse biomass, paving the way towards a sustainable, circular society. [ABSTRACT FROM AUTHOR]

المؤلفون: Cen, Xianyi¹ (AUTHOR), Fang, Yuhao¹ (AUTHOR), Chen, Zilong² (AUTHOR), Zhu, Xinhai² (AUTHOR) zhuxinh@mail.sysu.edu.cn

المصدر: Rapid Communications in Mass Spectrometry: RCM. Jul2024, Vol. 38 Issue 13, p1-14. 14p.

مصطلحات موضوعية: *MATRIX-assisted laser desorption-ionization, *TIME-of-flight mass spectrometry, *BENZIMIDAZOLES, *BENZIMIDAZOLE derivatives, *ANIONS, *MATRIX effect, *PROTON affinity

مستخلص: Rationale: With the development of matrix‐assisted laser desorption/ionisation (MALDI) mass spectrometry (MS) in spatial localisation omics research on small molecules, the detection sensitivity of the matrix must increase. However, the types of matrices suitable for detecting acidic small molecules in (−) MALDI‐MS mode are very limited and are either not sensitive enough or difficult to obtain. Methods: More than 10 commercially available benzimidazole and benzothiazole derivatives were selected as MALDI matrices in negative ion mode. MALDI‐MS analysis was performed on 38 acidic small molecules and mouse serum, and the matrix effects were compared with those of the common commercial matrices 9‐aminoacridine (9AA), 1,5‐naphthalenediamine (DAN) and 3‐aminoquinoline (3AQ). Moreover, the proton affinity (PA) of the selected potential matrix was calculated, and the relationships among the compound structure, PA value and matrix effect were discussed. Results: In (−) MALDI‐MS mode, a higher PA value generally indicates a better matrix effect. Amino‐substituted 2‐phenyl‐1H‐benzo[d]imidazole derivatives had well‐defined matrix effects on all analytes and were generally superior to the commonly used matrices 9AA, DAN and 3AQ. Among them, 2‐(4‐(dimethylamino‐phenyl)‐1H‐benzo[d]imidazole‐5‐amine (E‐4) has the best sensitivity and versatility for detecting different analytes and has the best ability to detect fatty acids in mouse serum; moreover, the limit of detection (LOD) of some analytes can reach as low as ng/L. Conclusions: Compared to 9AA, DAN and 3AQ, matrix E‐4 is more effective at detecting low‐molecular‐weight acidic compounds in (−) MALDI‐MS mode, with higher sensitivity and better versatility. In addition, there is a clear correlation between compound structure, PA and matrix effects, which provides a basis for designing more efficient matrices. [ABSTRACT FROM AUTHOR]

المؤلفون: Chaumeau, Victor^1,2 (AUTHOR) victor@shoklo-unit.com, Piarroux, Martine³ (AUTHOR), Kulabkeeree, Thithiworada¹ (AUTHOR), Sawasdichai, Sunisa¹ (AUTHOR), Inta, Aritsara¹ (AUTHOR), Watthanaworawit, Wanitda¹ (AUTHOR), Nosten, François^1,2 (AUTHOR), Piarroux, Renaud³ (AUTHOR), Nabet, Cécile³ (AUTHOR)

المصدر: PLoS ONE. 7/5/2024, Vol. 19 Issue 7, p1-16. 16p.

مصطلحات موضوعية: *TIME-of-flight mass spectrometry, *MATRIX-assisted laser desorption-ionization, *DESORPTION ionization mass spectrometry, *ANOPHELES, *MASS spectrometry, *MOSQUITOES, *SPECIES

مصطلحات جغرافية: SOUTHEAST Asia, MYANMAR, THAILAND

مستخلص: Malaria elimination in Southeast Asia remains a challenge, underscoring the importance of accurately identifying malaria mosquitoes to understand transmission dynamics and improve vector control. Traditional methods such as morphological identification require extensive training and cannot distinguish between sibling species, while molecular approaches are costly for extensive screening. Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as a rapid and cost-effective tool for Anopheles species identification, yet its current use is limited to few specialized laboratories. This study aimed to develop and validate an online reference database for MALDI-TOF MS identification of Southeast Asian Anopheles species. The database, constructed using the in-house data analysis pipeline MSI2 (Sorbonne University), comprised 2046 head mass spectra from 209 specimens collected at the Thailand-Myanmar border. Molecular identification via COI and ITS2 DNA barcodes enabled the identification of 20 sensu stricto species and 5 sibling species complexes. The high quality of the mass spectra was demonstrated by a MSI2 median score (min-max) of 61.62 (15.94–77.55) for correct answers, using the best result of four technical replicates of a test panel. Applying an identification threshold of 45, 93.9% (201/214) of the specimens were identified, with 98.5% (198/201) consistency with the molecular taxonomic assignment. In conclusion, MALDI-TOF MS holds promise for malaria mosquito identification and can be scaled up for entomological surveillance in Southeast Asia. The free online sharing of our database on the MSI2 platform (https://msi.happy-dev.frTest/) represents an important step towards the broader use of MALDI-TOF MS in malaria vector surveillance. [ABSTRACT FROM AUTHOR]

المؤلفون: Mei, Yudan¹ (AUTHOR), Hu, Yumei^2,3 (AUTHOR), Tao, Xiaoqian^2,3 (AUTHOR), Shang, Jing^2,3 (AUTHOR), Qian, Mengyu^2,3 (AUTHOR), Suo, Fengtai^2,3 (AUTHOR), Li, Jifeng^2,3 (AUTHOR), Cao, Liang^2,3 (AUTHOR), Wang, Zhenzhong^2,3 (AUTHOR), Xiao, Wei^1,2,3 (AUTHOR) xw_kanion@163.com

المصدر: Journal of Chromatographic Science. Jul2024, Vol. 62 Issue 6, p534-553. 20p.

مصطلحات موضوعية: *EMODIN, *TIME-of-flight mass spectrometry, *CHINESE medicine, *CHRONIC kidney failure, *ACYL group, *MULTIVARIATE analysis, *BIOACTIVE compounds

مستخلص: Shen-Wu-Yi-Shen tablets (SWYST) is a traditional Chinese medicine prescription used for treating chronic kidney disease (CKD). This study aims to characterize the constituents in SWYST and evaluate the quality based on the quantification of multiple bioactive components. SWYST samples were analyzed with ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and a data-processing strategy. As a result, 215 compounds in SWYST were unambiguously identified or tentatively characterized, including 14 potential new compounds. Meanwhile, strategies based on characteristic fragments for rapid identification were summarized, indicating that the qualitative method is accurate and feasible. Notably, the glucose esters of laccaic acid D-type anthraquinone were first found and their fragmentation patterns were described by comparing that of O -glycoside isomers. Besides, based on comparisons of the cleavage ways of mono-acyl glucose with different acyl groups or acylation sites, differences in fragmentation pathways between 1,2-di- O -acyl glucose and 1,6-di- O -acyl glucose were proposed for the first time and verified by reference substances. In addition, a validated UPLC-DAD was established for the determination of 11 major bioactive components related to treatment of CKD (albiflorin, paeoniflorin, 2,3,5,4′-tetrahydroxy-stilbene-2- O - β - d -glucoside (TSG), 1- O -galloyl-2- O -cinnamoyl- β - d -glucose, emodin-8- O - β - d -glucoside, chrysophanol- O - β - d -glucoside, aloe-emodin, rhein, emodin, chrysophanol and physcion). Moreover, TSG and 1- O -galloyl-2- O -cinnamoyl- β - d -glucose were found as the quality markers related to the origins of SWYST based on multivariate statistical analysis. Conclusively, the findings in this work provide a feasible reference for further studies on quality research and mechanisms of action in treating CKD. [ABSTRACT FROM AUTHOR]

المؤلفون: Dalgic, Mete Sungur¹ (AUTHOR), Weidner, Steffen¹ (AUTHOR) steffen.weidner@bam.de

المصدر: Rapid Communications in Mass Spectrometry: RCM. Jun2024, Vol. 38 Issue 12, p1-9. 9p.

مصطلحات موضوعية: *MATRIX-assisted laser desorption-ionization, *TIME-of-flight mass spectrometry, *POLYMER blends, *METHYL methacrylate, *ETHYLENE glycol, *DESORPTION, *LASERS

مستخلص: Rationale: Solvent‐free sample preparation offers some advantages over solvent‐based techniques, such as improved accuracy, reproducibility and sensitivity, for matrix‐assisted laser desorption/ionization (MALDI) analysis. However, little or no information is available on the application of solvent‐free techniques for the MALDI analysis of polymer blends. Methods: Solvent‐free sample preparation by ball milling was applied with varying sample‐to‐matrix ratios for MALDI time‐of‐flight mass spectrometry analysis of various polymers, including polystyrenes, poly(methyl methacrylate)s and poly(ethylene glycol)s. The peak intensity ratios were compared with those obtained after using the conventional dried droplet sample preparation method. In addition, solvent‐assisted milling was also applied to improve sample homogeneities. Results: Depending on the sample preparation method used, different peak intensity ratios were found, showing varying degrees of suppression of the signal intensities of higher mass polymers. Ball milling for up to 30 min was required to achieve constant intensity ratios indicating homogeneous mixtures. The use of wet‐assisted grinding to improve the homogeneity of the blends was found to be disadvantageous as it caused partial degradation and mass‐dependent segregation of the polymers in the vials. Conclusions: The results clearly show that solvent‐free sample preparation must be carefully considered when applied to synthetic polymer blends, as it may cause additional problems with regard to homogeneity and stability of the blends. [ABSTRACT FROM AUTHOR]

المؤلفون: Zhao, Xueyan¹ (AUTHOR), Zheng, Lihui² (AUTHOR), Shi, Qingxin¹ (AUTHOR), Lin, Yuqi¹ (AUTHOR), Zeng, Zhaoxiang¹ (AUTHOR), Song, Chengwu^1,3 (AUTHOR), Jin, Shuna^3,4 (AUTHOR) jinshuna2021@hbtcm.edu.cn, Xiao, Ling² (AUTHOR) Lingyun724@126.com

المصدر: Hereditas. 6/21/2024, Vol. 161 Issue 1, p1-11. 11p.

مصطلحات موضوعية: *TIME-of-flight mass spectrometry, *METABOLITES, *PHARMACOGNOSY, *SECONDARY analysis, *PLANT metabolites, *CHINESE medicine

مستخلص: The Balanophorae are not only traditional Chinese herbal medicines but also functional foods with diverse sources. This study aimed to distinguish pharmacognostic characteristics and secondary metabolites among different species of Balanophorae. Eight species of Balanophorae herbs were harvested, including 21 batches with 209 samples. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was used to analyze secondary metabolites of Balanophorae from 21 sources. Targeted metabolomic analysis was performed to compare differences among the groups. Rhopalocnemis phalloide and B. indica can be identified by their pharmacognostic characteristics. Then, 41 secondary metabolites were identified or characterized in the mixed extracts of the 209 samples, mainly phenolic acids, flavonoids, and their derivatives. The distribution of these secondary metabolites revealed apparent differences among different species. In addition, targeted metabolomic analysis suggested that the secondary metabolite profiles of seven species of Balanophorae showed noticeable differences, and differences were also observed among different growing regions. Finally, five important metabolic markers were screened to successfully distinguish B. laxiflora, B. harlandii, and B. polyandra, including three phenolic acids and two flavonoids. This is the first study to systematically compare both the morphology and secondary metabolites among different sources of Balanophorae, which could provide effective information for identifying diverse species. [ABSTRACT FROM AUTHOR]

المؤلفون: Dickel, Timo^1,2 (AUTHOR) T.dickel@gsi.de, Mollaebrahimi, Ali^2,3 (AUTHOR)

المصدر: European Physical Journal: Special Topics. Jun2024, Vol. 233 Issue 5, p1181-1190. 10p.

مصطلحات موضوعية: *TIME-of-flight mass spectrometry, *NUCLEAR research, *MASS spectrometry, *ISOMERS, *NUCLEAR structure, *EXCITED states

مستخلص: Nuclear isomers, the excited meta-stable states of nuclei, offer profound insights into nuclear structure. This article reviews the intersection of nuclear isomer research with mass spectrometry methodologies, particularly focusing on novel capabilities of the multiple-reflection time-of-flight mass spectrometry (MR-TOF-MS) technique. Through a comprehensive examination of established methods for isomer identification and characterization, alongside the technical principles underlying MR-TOF-MS, this review discusses the pivotal role of mass spectrometry in advancing our understanding of nuclear isomers. The operational principles and recent developments in MR-TOF-MS technology are explained and exemplified through case studies from prominent research facilities. Furthermore, this work discusses ongoing efforts to enhance sensitivity, resolution, and measurement capabilities in MR-TOF-MS, promising continued advancements in nuclear physics research and applications. [ABSTRACT FROM AUTHOR]