Vacuum ultraviolet(VUV) photolysis is recognized as an environmental-friendly treatment process. Nitrate(NO-3) and natural organic matter(NOM) are widely present in water source.We investigated trichloronitromethane(T...Vacuum ultraviolet(VUV) photolysis is recognized as an environmental-friendly treatment process. Nitrate(NO-3) and natural organic matter(NOM) are widely present in water source.We investigated trichloronitromethane(TCNM) formation during chlorination after VUV photolysis, because TCNM is an unregulated highly toxic disinfection byproduct. In this study:(1) we found reactive nitrogen species that is generated under VUV photolysis of NO-3react with organic matter to form nitrogen-containing compounds and subsequently form TCNM during chlorination;(2) we found the mere presence of 0.1 mmol/L NO-3can result in the formation of up to 63.96 μg/L TCNM;(3) we found the changes in pH(6.0-8.0), chloride(1-4 mmol/L), and bicarbonate(1-4 mmol/L) cannot effectively diminish TCNM formation;and,(4) we established the quantitative structure-activity relationship(QSAR) model,which indicated a linear relationship between TCNM formation and the Hammett constant(σ) of model compounds;and,(5) we characterized TCNM precursors in water matrix after VUV photolysis and found 1161 much more nitrogen-containing compounds with higher aromaticity were generated. Overall, this study indicates more attention should be paid to reducing the formation risk of TCNM when applying VUV photolysis process at scale.展开更多
The detailed glycan structural analysis of glycoprotein is amenable to glycopeptide enrichment. Here, we develop a simple, effective and economical approach to enrich glycopeptides from proteolytically digested peptid...The detailed glycan structural analysis of glycoprotein is amenable to glycopeptide enrichment. Here, we develop a simple, effective and economical approach to enrich glycopeptides from proteolytically digested peptide mixtures by chromatographic column packed with graphite carbon and activated charcoal (G/A-column). Glycopeptide from ovalbumin was efficiently enriched by homemade G/A-column using liquid chromatography and the structure of glycopeptide was obtained by tandem mass spectrometry using Fourier transform ion cyclotron resonance mass spectrometry. The results in this study demonstrate that G/A-column can be used to enrich N-glycolpeptides and be benefit for online identification of glycopeptide using LC-MS.展开更多
Dissolved organic matter(DOM) plays an essential role in many geochemical processes,however its complexity, chemical diversity, and molecular composition are poorly understood. Soil samples were collected from 500 veg...Dissolved organic matter(DOM) plays an essential role in many geochemical processes,however its complexity, chemical diversity, and molecular composition are poorly understood. Soil samples were collected from 500 vegetable fields in administrative regions of China' Mainland, of which 122 were selected for further investigation. DOM properties were characterized by three-dimensional excitation-emission matrix(3D-EEM) fuorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry(FTICRMS)(field intensity is 15 Tesla). Our results indicated that the main constituents were UVA humic-like substances, humic-like substances, fulvic acid-like substances, and tyrosine-like substances. A total of 10,989 molecular formulae with a mass range of 100.04 to 799.59 Da were detected, covering the mass spectrometric information of the soil samples from 27 different regions. CHO and CHON molecules were dominant in DOM, whereas lignin, tannins,and aromatic substances served as the main components. The results of cluster analysis revealed that the soil properties in Jiangxi Province were considerably different from those in other regions. The key backgrounds of the DOM molecular characteristics in the vegetablefield soil samples across China' Mainland were provided at the molecular level, with large abundance and great variability.展开更多
基金supported by Natural Science Foundation of Hunan Province (No. 2021JJ40066)National Natural Science Foundation (Nos. 51878257 and 52100007).
文摘Vacuum ultraviolet(VUV) photolysis is recognized as an environmental-friendly treatment process. Nitrate(NO-3) and natural organic matter(NOM) are widely present in water source.We investigated trichloronitromethane(TCNM) formation during chlorination after VUV photolysis, because TCNM is an unregulated highly toxic disinfection byproduct. In this study:(1) we found reactive nitrogen species that is generated under VUV photolysis of NO-3react with organic matter to form nitrogen-containing compounds and subsequently form TCNM during chlorination;(2) we found the mere presence of 0.1 mmol/L NO-3can result in the formation of up to 63.96 μg/L TCNM;(3) we found the changes in pH(6.0-8.0), chloride(1-4 mmol/L), and bicarbonate(1-4 mmol/L) cannot effectively diminish TCNM formation;and,(4) we established the quantitative structure-activity relationship(QSAR) model,which indicated a linear relationship between TCNM formation and the Hammett constant(σ) of model compounds;and,(5) we characterized TCNM precursors in water matrix after VUV photolysis and found 1161 much more nitrogen-containing compounds with higher aromaticity were generated. Overall, this study indicates more attention should be paid to reducing the formation risk of TCNM when applying VUV photolysis process at scale.
文摘The detailed glycan structural analysis of glycoprotein is amenable to glycopeptide enrichment. Here, we develop a simple, effective and economical approach to enrich glycopeptides from proteolytically digested peptide mixtures by chromatographic column packed with graphite carbon and activated charcoal (G/A-column). Glycopeptide from ovalbumin was efficiently enriched by homemade G/A-column using liquid chromatography and the structure of glycopeptide was obtained by tandem mass spectrometry using Fourier transform ion cyclotron resonance mass spectrometry. The results in this study demonstrate that G/A-column can be used to enrich N-glycolpeptides and be benefit for online identification of glycopeptide using LC-MS.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program (STEP,No.2019QZKK0304)the Fundamental Research Funds for the Central Universities (No.E2EG0502×2)the Natural Science Foundation Committee of China (No.41991310)。
文摘Dissolved organic matter(DOM) plays an essential role in many geochemical processes,however its complexity, chemical diversity, and molecular composition are poorly understood. Soil samples were collected from 500 vegetable fields in administrative regions of China' Mainland, of which 122 were selected for further investigation. DOM properties were characterized by three-dimensional excitation-emission matrix(3D-EEM) fuorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry(FTICRMS)(field intensity is 15 Tesla). Our results indicated that the main constituents were UVA humic-like substances, humic-like substances, fulvic acid-like substances, and tyrosine-like substances. A total of 10,989 molecular formulae with a mass range of 100.04 to 799.59 Da were detected, covering the mass spectrometric information of the soil samples from 27 different regions. CHO and CHON molecules were dominant in DOM, whereas lignin, tannins,and aromatic substances served as the main components. The results of cluster analysis revealed that the soil properties in Jiangxi Province were considerably different from those in other regions. The key backgrounds of the DOM molecular characteristics in the vegetablefield soil samples across China' Mainland were provided at the molecular level, with large abundance and great variability.
